מחקר

Solar Cells

• High-voltage nanoporous Solar Cells(G. Hodes)

Biomass

• Engineering Green Algae for Biodiesel(U. Pick, A. Danon)
• Cellulose biomass for biofuels(E. Bayer, G. Schreiber, D. Tawfik)

Fusion

• Optimizing Energy Conversion for Nuclear Fusion(Y . Maron)

Artificial Photosynthesis

• Catalytic Conversion of CO2(D. Milstein, R. Neumann, J.M. L Martin)

Basic research for Biofuels

• Engineering High-Lipid Content in Marine Algae(A. Aharoni, A. Vardi)
• Engineering cyanobacteria for biomass and biodiesel(A.Scherz)
• Institute-wide consortium(A. Levy, Y. Eshed, A. Danon, U. Pick, E. Bayer, G. Galili, N. Barkai)

Solar Cells

• Molecules for Inverted Solar Cells(M. Van Der Boom)
• High-voltage nano-porous Solar Cells(G. Hodes)

Artificial Photosynthesis

• Reconstitution of oxygenic photosystem by incorporating in sol-gel matrices(D. Noy)
• Catalytic Reduction of CO2(R. Neumann)

Nuclear Fission

• New nuclear-energy scheme and radioactive waste treatment(M. Hass)

Energy Analysis & Sustainability

• GeoNumbers – Earth & energy numbers database(R. Milo)
• EcoDollars: environmental cost of products(R. Milo)

New Options for Solar Energy Conversion to Biofuel and Electricity - Biofuels

• Biofuels(Levy, Barkai, Milo, Bayer, Aharoni)

  We aim at developing new energy-rich biomass sources, genetically engineered or selected from natural biodiversity, as biofuel feedstock and optimize biofuel production from the new biomass sources. 

New Options for Solar Energy Conversion to Biofuel and Electricity - Optics

• Optics(Oron, Prior, Davidson)

  We aim at developing new methods for light concentration from macroscopic to microscopic scale, and means to use concentrated light for improved light harvesting efficiency

Other Projects

• Homogeneously Microstructured Metal-Organic Frameworks for Efficient Energy Storage, Transport, and Release(van der Boom)

  Replacing our polluting, oil-driven economy with one based on renewable and clean energy sources requires advanced materials that can store, transport, and release this energy in the form of gaseous compounds. However, the efficient storage of energy in the form of dihydrogen (or methane, carbon mono-oxide), and its controlled release at practical temperature ranges and at constant and mild pressures is a challenging task. The aim of the proposed project is to be able to generate highly porous, uniform, and robust molecular materials that might be used in diverse real-world applications, including vehicles running on dihydrogen.

New Options for Solar Energy Conversion to Biofuel and Electricity

• New Options for Solar Energy Conversion to Biofuel and Electricity(The Leona M. and Harry B. Helmsley Charitable Trust)

  The program will involve dozens of researchers from Weizmann Institute of Science and the Technion – Israel Institute of Technology. In it scientists in fields ranging from genetics and plant sciences to chemistry, physics and engineering will be working together toward the common goal of providing renewable energy options to Israel and the world. For another, the researchers anticipate that wedding the basic research approach of the Weizmann Institute to the advanced technical-engineering emphasis of the Technion teams will provide the synergy needed to accelerate discovery and development of innovative energy options that can be the basis for future technologies.

  In addition to advancing new avenues of research, the new gift will serve to expand and strengthen the success of existing alternative energy programs, including the Weizmann Institute’s Alternative Energy Research Initiative (AERI), the Grand Technion Energy Program (GTEP) and the Israeli Center of Research Excellence (ICORE) in alternative energy. The Weizmann Institute and Technion participate along with the Ben-Gurion University of the Negev in the latter.

  Initially, the research projects will focus on three key areas: biofuels, photovoltaics and optics for light harvesting. The biofuels research includes generating effective methods for breaking down waste plant matter into usable fuel resources, developing algae that can produce biofuels economically and developing plants that can be grown sustainably and provide materials that can easily be converted to biofuel. The Helmsley initiative will help fund state-of-the-art facilities at the Weizmann Institute to advance this research.

  The other two areas of focus – photovoltaics and optics – will include the creation of new materials that can use a larger portion of the sun’s energy (today’s cells use only a limited part of the sunlight) and innovative ways of efficiently converting that energy to electricity. The optics research will involve some of the most cutting-edge materials design and research available, including plasmonics, nanostructures and metamaterials studies.

  The Weizmann Institute’s Prof. David Cahen heads the Helmsley project together with Prof. Gideon Grader of the Technion. They expect that a number of the research teams will find themselves working in all three areas in parallel, as the best solutions, including the more distant goal of artificial photosynthesis, are likely to involve combinations of the three. 

New Options for Solar Energy Conversion to Biofuel and Electricity - Photovoltaics

• Photovoltaics(Cahen, Hodes, Bendikov, Kronik)

  Our aim is to identify and understand the limits to organic solar cells and explore how to overcome these limits.

• Optics Research(Oron, Prior, Davidson)

  The ability of Prof. Dan Oron and his group to design and synthesize novel nanoscale semiconductor materials enabled them to develop a new class of nonlinear upconversion materials exhibiting relatively efficient photon upconversion. The group has also studied the use of compound semiconductor nanocrystals in photovoltaic cells either as sensitizers or in order to optimize the current-voltage characteristics by modification of the band alignment within the cell upon photoexcitation via the concept of photoinduced dipoles. The type-II nanocrystal sensitized system first studied by the Oron group has recently led to the highest efficiency semiconductor sensitized solar cell demonstrated, reaching nearly 8%. In parallel, Oron’s group has collaborated with the group of G. Frey (Technion) on the topic of hybrid organic-inorganic photovoltaics. 

  The main challenge we face today is enhancing the efficiency and simplifying the fabrication of upconversion nanostructures. We are approaching this by harnessing self-assembly of simple nanocrystalline building blocks rather than a multi-step synthesis of complex ones.

  Another front where we are currently struggling to make progress is fabrication of intermediate band sensitized solar cells, where a proof-of principle experiment was successful, but where better control over the system is necessary to obtain quantitative results.

  Work in Prof. Yehiam Prior’s group focused on the enhancement of nonlinear optical interactions by plasmonic cavity antennae. It was shown that nanocavities perform very differently from the more conventional nanoparticle antennae due to longer range coupling between them. This led to the development of new structures to be used for enhancement of second harmonic generation, by taking advantage of the coupling phenomenon. More recently, the group has shown that nanocavity arrays can be tailored for enhancement of the more general nonlinear process of four-wave mixing, and that spectral tuning is readily achievable by modifying the geometrical parameters of the array. All these ‘global’ nonlinear optical measurements were supplemented by both state-of-the art local measurements and detailed numerical simulations.

  The main challenge we are faced with today is the generalization and optimization of the enhancement process. There are many parameters to consider such as film thickness and composition, cavity size and structural periodicities, shapes with more complex symmetries, coupled cavities of different degree of coupling, and quite a few other parameters. Like many other examples, optimization in a multi-dimensional space is rather complex and one often resorts to computer algorithms and loses physical insight.

  Prof. Nir Davidson and his group focused on concentration of solar radiation close to the thermodynamic limit using the principle of phase space conservation. We applied this principle to compact concentrations based on reflective optical elements where chromatic aberrations do not exist. Specifically, a 3 mirror concentrator was shown to achieve concentration ratio >95% of the thermodynamic limit for realistic solar parameters. Such high concentration enables the use of high efficiency low area solar cells while maintaining low cost, without the need for an pre-concentration stage. We also applied the principle of phase space conservation to optical concentrators based on Fresnel lenses which work in transmission providing more flexibility in the system design.

  The main challenge we are faced with today is to apply the concept of anamorphic diffuse light concentrators, proposed in our group in the past, into solar concentration where chromatic aberrations prevent the use of diffractive optics. We will use both tapered reflecting tubes and multi-faceted reflective and refractive optical elements to provide the needed coupling between the two transverse directions to transfer brightness from one direction to the other so as to obtain in one dimension higher concentration while conserving the total brightness. Our preliminary results validate the applicability of these concepts to anamorphic solar concentration.
• Biofuels(Levy, Barkai, Milo, Bayer, Aharoni)

  We take a multidisciplinary approach aimed at addressing major challenges in biomass production (Prof. Abraham Levy), analysis, design (Profs. Ron Milo and Asaph Aharoni) and processing, from the deconstruction of the cellulosic biomass into sugars (Prof. Ed Bayer), to fermentation into alcohol (Prof. Naama Barkai).

  We used a variety of tools from genetics and genomics (Levy and Barkai), biochemistry (Bayer), computational and microbial biology for pathway design (Milo) and sophisticated advanced analytical techniques for biomass composition analyses (Aharoni). All the projects have accomplished significant achievements towards the development of new generations of biofuels that will not compete with food.
• Photovoltaic Research(Cahen, Hodes, Rybtchinski, Kronik)

  Profs. Gary Hodes and David Cahen focus on high voltage photovoltaic cells for use in tandem solar cells and photochemical production of chemicals. Very early in the project, hybrid perovskite photovoltaic cells (most commonly CH3NH3PbI3) burst on the scene and are now a major research area with their teams and in the world in general.

  In the non-perovskite work, they showed how the work function (an important property for photovoltaic cells and all electronic devices) of zinc oxide (ZnO) could be tuned over a large range by adsorption of molecules; and explained how surface oxidation of cadmium selenide (CdSe) nanocrystals increased the photovoltage of cells based on this material.

  Prof. Boris Rybtchinski investigated the crystallization parameters relevant to fabrication of perovskite materials based on CH3NH3PbI3 and CH3NH3PbBr3. In collaboration with Profs. Hodes and Cahen, they found that the addition of PbCl2 to the solutions used in the perovskite synthesis has a remarkable effect on the end product, because PbCl2 nanocrystals are present during the fabrication process, acting as heterogeneous nucleation sites for the formation of perovskite crystals in solution. This conclusion was based on scanning electron microscope (SEM) studies, synthesis of perovskite single crystals, and on cryo-TEM (transmission electron microscope) imaging of the frozen mother liquid. Their studies also included the effect of different substrates and substrate temperatures on the perovskite nucleation efficiency.

  In view of these findings, they optimized the procedures for solar cells based on lead bromide perovskite, resulting in 5.4% efficiency at a Voc of 1.24 V, improving the efficiency in this class of devices. These findings have been published in a collaborative paper (Tidhar, Yaron; Edri, Eran; Weissman, Haim; Zohar, Dorin; Hodes, Gary; Cahen, David; Rybtchinski, Boris; Kirmayer, Saar. Crystallization of Methyl Ammonium Lead Halide Perovskites: Implications for Photovoltaic Applications. J. Am. Chem. Soc. 2014, 136, 13249–13256). Importantly, in this project, a cryo- TEM methodology was developed for imaging organic solutions used for fabricating solar devices.

  In addition, they investigated the influence of HTL/perovskite interfaces on the performance of MAPbBr3-based devices, unraveling details of morphological and electronic changes upon interaction of organic HTLs with perovskite surface. They discovered that simple organic salts in combination with dielectric polymers can lead to relatively efficient (4%) solar cells, underlying the possibility that perovskite cells may not need an electronically active HTL. They also obtained insights into the electronic properties of the devices using UPS. A manuscript describing this work is in preparation.

  Prof. Leeor Kronik developed new theoretical approaches to extend density functional theory for evaluating new photovoltaic materials. These efforts have recently been extended to the important case of the optical properties of solid-state materials. In parallel, Prof. Kronik has studied the structural properties of hybrid organic-inorganic perovskites, an exciting new class of solar cell materials. His work exposed the importance of dispersive interactions in these materials and revealed the possibility for hydrogen migration in them.

Other Projects

• Remodeling lipid Content in Marine Algae by Bio-Mimicking of Metabolic Strategies Used by Algal Viruses(Dr. Assaf Vardi)

  The world fossil oil reserves will be exhausted in less than 50 years. Therefore, renewable, carbon neutral, economically viable alternatives are urgently needed. The growing interest in microalgae for oil production is due to their relatively high lipid content and the new genetic and genomic resources that are currently available. We (re)discovered that a marine algal virus has evolved unique metabolic strategies to infect its host by profoundly remodeling its lipid metabolism. Our long-term goal is to unfold some of the molecular secrets used during viral infection and mimic these metabolic principles to enhance lipid production for future biofuel application.
• Homogeneously Microstructured Metal-Organic Frameworks for Efficient Energy Storage, Transport and Release(Prof. Milko van der Boom)

  We obtained porous materials that can efficiently store and release energy (natural gas and dihydrogen) at low pressure (J. Am. Chem. Soc. 2015, 137, 226-231). Dihydrogen can be generated from renewable energy resources. Our materials might find real-world applications in motor vehicles and transport ships. The use of these gases will significantly reduce the emission of greenhouse gases. Yeda filed for patent protection, and the IP has been licensed to a start-up company.

  We also designed colorful coatings for smart-window technology to reduce energy consumption for cooling and heating of buildings. Our coatings become transparent upon applying a low voltage. Their coloration can be cycled for at least 100,000 times (J. Am. Chem. Soc., 2015, 137, 4050-4053). Yeda filed for patent protection. These materials might be further developed in industry. Our polypyridyl complexes were also applied as electron transporting materials for inverted bulk heterojunction solar cells: the metal center effect (J. Mater. Chem. C 2016, 4, 4634-4639 - cover page).
• Quantum Thermodynamics of Solar Devices as Heat Machines(Prof. Gershon Kurizki)

  We pursued a novel theoretical approach, derived from quantum thermodynamics, aimed at deeper understanding and optimization of solar-cell operation. This approach views a solar cell as a heat engine, i.e., a machine that transforms solar radiation into useful work. To this end we revisited the thermodynamic bounds of work extraction in simple model quantum heat machines subject to control by frequent modulations. The laws of thermodynamics are obeyed, yet the known bounds are found to be transgressed by certain quantum states, indicating that quantum resources can boost heat machine performance.

  Boosting the Conversion of Primary Metabolism into Aromatic Amino Acids as Precursors for the Production of Biofuel -Associated Volatilic Alcohols in Plants

  Prof. Gad Galili

  Fuel products are generally composed of volatile compounds, which enable their efficient evaporation and burning. Plants generally synthesize multiple volatile compounds, termed as secondary metabolites, which have efficient evaporation capabilities and hence this compounds can be highly suitable as biological fuels, also termed as biofuels. Plants synthesize a large number of volatile compounds, also termed as volatile metabolites, and use them for various biological reasons; yet, these plant-derived volatile compounds could also serve as efficient biofuel products. Our long-term goal is to stimulate the production of such plant-based volatile compounds, so that they could be used for various processes, an example of which are volatile biofuels that could be used as petrol-like compounds in cars, thus reducing the risk of a shortage of fuels extracted from the earth.
• Boosting the Conversion of Primary Metabolism into Aromatic Amino Acids as Precursors for the Production of Biofuel -Associated Volatilic Alcohols in Plants(Prof. Gad Galili)

  Fuel products are generally composed of volatile compounds, which enable their efficient evaporation and burning. Plants generally synthesize multiple volatile compounds, termed as secondary metabolites, which have efficient evaporation capabilities and hence this compounds can be highly suitable as biological fuels, also termed as biofuels. Plants synthesize a large number of volatile compounds, also termed as volatile metabolites, and use them for various biological reasons; yet, these plant-derived volatile compounds could also serve as efficient biofuel products. Our long-term goal is to stimulate the production of such plant-based volatile compounds, so that they could be used for various processes, an example of which are volatile biofuels that could be used as petrol-like compounds in cars, thus reducing the risk of a shortage of fuels extracted from the earth.
• Regulation and Biosynthesis of Algal Lipid Bodies(Profs. Avihai Danon and Uri Pick, with Dr. Assaf Vardi, and Profs. Avigdor Scherz and Asaph Aharoni)

Nuclear Fission

• New nuclear energy scheme & radioactive waste treatment(M. Hass)

Biomass

• Alternative Carbon Fixation Cycles for Increased Productivity and Sustainable Energy(R. Milo)

Solar Cells

• Molecules for Inverted Solar Cells(M. Van Der Boom)
• Quantum dot Solar Cells(Dan Oron)
• High-voltage nanoporous Solar Cells(G. Hodes)

Artificial Photosynthesis

• Reconstitution of oxygenic photosystem by incorporating in sol-gel matrices(D. Noy)
• Catalytic Conversion of CO2(D. Milstein, R. Neumann, J.M.L. Martin)

Energy Analysis & Sustainability

• GeoNumbers – Earth & energy numbers database(R. Milo)
• EcoDollars: environmental cost of products(R. Milo)

Designing a Better Thermoelectric Material

• Special grant(Y. Imry)

Artificial Photosynthesis

• Storage of Electrical Energy via CO(I. Lubomirsky)
• Catalytic Conversion of CO2(D. Milstein, R. Neumann, J.M. L Martin)
• Nanoparticle-molecule hybrid Solar Energy Conversion(I. Rudich, B. Rybtchinski, R. Naaman, G. Hodes, L. Kronik)

Biomass

• Engineering Green Algae for Biodiesel(U. Pick, A. Danon)
• Cellulose biomass for biofuels(E. Bayer, G. Schreiber, D. Tawfik)
• Engineering Cyanobacteria for Biomass and Hydrogen(D. Noy, A. Scherz)

Nuclear Fusion

• Optimizing Energy Conversion in Nuclear Fusion(Y. Maron)

New Options for Solar Energy Conversion to Biofuel and Electricity

• New Options for Solar Energy Conversion to Biofuel and Electricity(Supported by The Leona M. and Harry B. Helmsley Charitable Trust)

  We aim at developing new energy-rich biomass sources, genetically engineered or selected fromnatural biodiversity, as biofuel feedstock and optimize biofuel production from the new biomass sources.

  We have discovered wheat lines with highly digestible straw that could serve as feedstock for biofuel production (Levy, Barkai).

  We are working on the expression of proteins in vivo for testing synthetic pathways for carbon fixation, predicted from computational design (Milo).

  We have identified pretreatment conditions for the wheat straw substrate, which enables the native cellulosomes to completely convert the substrate into soluble saccharides for biofuel production (Bayer).

  We have created new analytical infrastructures, with cutting-edge equipment that is unique in Israel for the analysis of lipids and carbohydrates involved in biofuel production (Aharoni).

New Options for Solar Energy Conversion to Biofuel and Electricity - Biofuels

• Biofuels(Levy, Barkai, Milo, Bayer, Aharoni)

  We aim at developing new energy-rich biomass sources, genetically engineered or selected fromnatural biodiversity, as biofuel feedstock and optimize biofuel production from the new biomass sources.

  We have discovered wheat lines with highly digestible straw that could serve as feedstock for biofuel production (Levy, Barkai).

  We are working on the expression of proteins in vivo for testing synthetic pathways for carbon fixation, predicted from computational design (Milo).

  We have identified pretreatment conditions for the wheat straw substrate, which enables the native cellulosomes to completely convert the substrate into soluble saccharides for biofuel production (Bayer).

  We have created new analytical infrastructures, with cutting-edge equipment that is unique in Israel for the analysis of lipids and carbohydrates involved in biofuel production (Aharoni).

New Options for Solar Energy Conversion to Biofuel and Electricity - Optics

• Optics(Oron, Prior, Davidson)

  We aim at developing new methods for light concentration from macroscopic to microscopicscale, and means to use concentrated light for improved solar light harvesting efficiency for quantum conversion to electricity or fuels.

  We focus on luminescent and other solar light concentrators, up-converters, and on hybridized plasmonic-semiconductor nonlinear optics (Oron, Davidson, Prior). We created luminescence up-conversion via nanocrystals with efficiencies of ~0.1%, at par with rare-earth based nanocrystals (Oron).

  Using incoherent luminescence for up-conversion, we created plasmonic nanocavities that exhibit over 100-fold signal enhancement due to sub-wavelength focusing of light.

New Options for Solar Energy Conversion to Biofuel and Electricity - Photovoltaics

• Photovoltaics(Cahen, Hodes, Rybtchinski, Bendikov, Oron)

  Our aim is to identify and understand the limits to organic solar cells and explore how to overcome these limits.

  Our most significant achievement in photovoltaic research so far has been our use of a real organic-inorganic hybrid material with the perovskite¹ structure for a high voltage photovoltaic cell. We demonstrated a low-voltage-loss cell with 1.3 V open-circuit voltage, and published the first article on this novel type of cell (“High Open-Circuit Voltage Solar Cells Based on Organic-Inorganic Lead Bromide Perovskite” Journal of Physical Chemistry Letters, 2013) (Cahen-Hodes).

  We have demonstrated a new hybrid silicon/organic inversion solar cell (Cahen).

  We have carried out extensive basic research on new “hole conductors” with a high potential for photovoltaic devices (Hodes, Rybtchinski, Bendikov). We performed and analyzed time-resolved characterization of organic/inorganic composites developed at the Technion for solar applications (Oron).

  Lastly, we have developed a methodology to compute, using a DFT-based approach, optical excitation gaps for gas phase organic molecules.

  --------------------------------------
  ¹ Made from a material with the same type of crystal structure as the mineral calcium titanium oxide (CaTiO3) known as perovskite.

Other Projects

• Homogeneously Microstructured Metal-Organic Frameworks for Efficient Energy Storage, Transport, and Release(van der Boom)

  Replacing our polluting, oil-driven economy with one based on renewable and clean energy sources requires advanced materials that can store, transport, and release this energy in the form of gaseous compounds. However, the efficient storage of energy in the form of dihydrogen (or methane, carbon mono-oxide), and its controlled release at practical temperature ranges and at constant and mild pressures is a challenging task. The aim of the proposed project is to be able to generate highly porous, uniform, and robust molecular materials that might be used in diverse real-world applications, including vehicles running on dihydrogen.

  We have obtained new porous materials with natural gas (CH₄) uptake capabilities that are reversible and comparable with commercially available Metal-Organic Frameworks (MOFs) such as Basolite. 
• Regulation and Biosynthesis of Algal Lipid Bodies(Danon, Pick, Vardi, Scherz, Aharoni)

  The natural ability of algae cells to accumulate high level of lipid-droplets serves as an attractive alternative for fossil fuel. Algae grow at very high rates, have high photosynthetic energy conversion efficiency, could use high level of CO₂, furthermore each algal cell is an oil producer. Algae can be mass cultivated on waste or saline water in large areas not accessible for agricultural cultivation, avoiding competition with food production. The extracted algae oil is a drop-in fuel, which can be put into an immediate use, as it is fully compatible with current distribution storage and engines. Based on our previous studies, we propose to study the molecular, biochemical and genetic regulation of lipid-droplets accumulation in algae, to identify and to use key genes that control lipiddroplets production in unicellular algae for maximizing biofuel production.
• Using flower petals as model system to elucidate plant genes controlling production of volatile alcohols having high biofuel properties(Galili)

  There is a major worldwide demand for new resources of energy, with plants being excellent sources of biofuel enhancing genes because their flowers produce multiple aromatic volatile compounds that could also be efficient biofuels. We plan to identify such volatile compounds and genes controlling their production, using petunia flowers that were genetically engineered to enhance the production of these volatile compounds from primary metabolism by transforming them with a bacterial gene proven to stimulate the conversion of primary to secondary metabolism. The identified candidate genes could later be introduced into other biological systems suitable for biofuel production, like photosynthetic algae.

Artificial Photosynthesis

• Catalytic Conversion of Carbon Dioxide for “C-Neutral” Energy(R. Neumann)
• Chemical Storage of Electrical Energy via Carbon Monoxide(I. Lubomirsky)
• Solar production of Hydrogen from water(B. Rybtchinski)

Biomass

• Engineering Green Algae for Biodiesel(U. Pick, A. Danon)
• Cellulose biomass to biofuels(E. Bayer, G. Schreiber, D. Tawfik)

Optics Research

• Plasmonically Enhanced Upconversion of Solar Light from Anamorphic Concentrators(Nir Davidson, Dan Oron, Yehiam Prior)

  Photovoltaic solar conversion is a commercially available and widely used technology. We address several key issues on the road to more efficient utilization of the available solar power: - design small scale cost effective solar concentrators which can concentrate more in one direction at the expense of the orthogonal direction and are based on durable reflective optical elements; - develop upconversion of infrared to visible light readily absorbed in the solar cells and utilized for charge separation, thus increasing the fraction of usable solar spectrum; use nonlinear plasmonics and rationally designed metal nanocavities for enhancing the optical interaction of the nanocrystals developed for the spectral conversion.

Photovoltaics

• Understanding Structure-Property Relations in Organic-Inorganic Hybrid Perovskites from First Principles(Leeor Kronik)

  Successful photovoltaic technology must combine high performance with low cost. Recently, organic-inorganic hybrid perovskites (OIHP), and especially methylammonium-lead-iodide (MAPbI3), have drawn enormous attention because they combine the outstanding semiconducting properties of inorganic semiconductors with the generally lower costs of organic crystals. However, little is known about defect behavior in these materials, and especially how its changes in time affect solar-cell performance and long-term stability. We aim to elucidate this behavior based on first-principles calculations, based on the atomic species involved and the laws of quantum mechanics. In such calculations, structural and chemical motifs can be created in a controlled manner and their properties examined systematically. This should afford a detailed understanding of mechanisms limiting cell performance and stability and therefore allow us to point out strategies for making further progress.
• Control over crystallization in hybrid organic/inorganic perovskite (HOIP) solar cells(Boris Rybtchinski, Gary Hodes)

  The field of HOIP solar cells has experienced a meteoric rise due to spectacular efficiencies (above 20%), low cost and simple fabrication. However, one of the key questions, namely how the active layer is formed, is not well understood, leading to unreliable fabrication methodologies, and lack of a scientific basis needed to improve HOIP devices. We address the issue of understanding and control over HOIP formation using unique methodologies developed in our groups, as well as our complementary expertise. Our research will create a basis for rational design and the discovery of new types of HOIP materials.

Storage

• Shedding Light on Processes at the Electrode Interface in Lithium Ion Batteries by Dynamic Nuclear Polarization and Solid State NMR(Michal Leskes)

  Lithium ion batteries are a leading technology for storage of renewable energy and electric transportation. An important criterion for these applications is prolonged performance with high energy density. A major cause for premature battery failure is the electrode - electrolyte interactions, with the cathode being the main source for energy loss which is poorly understood. Our main goal here is to gain insight into the chemistry and mechanism of the interactions on the cathode side and their deleterious effect on the lifetime of battery cells. Such insight can then provide guidelines for developing more durable battery cells.

Biofuels

• Alternative Carbon Fixation Cycles for Increased Productivity and Sustainable Energy(Ron Milo)

  Carbon fixation is the main pathway for storing energy and accumulating biomass in the living world. It also supplies our food and dominates humanity's usage of land and water. Under human cultivation, where water, light and nutrients can be abundant, it is the rate of carbon fixation that significantly limits growth. Hence increasing the rate of carbon fixation is of major importance in the path towards agricultural and energetic sustainability.We aim to construct and investigate a promising fully functional synthetic cycle for carbon fixation in the lab.
   
• Embedding Diverse Analytical Platforms in the Biofuel projects(Asaph Aharoni)

  Discovering of novel strategies for efficient biofuel production from renewable biomass sources is the main goal of biofuel research. The use of an analytical platform (so called 'metabolomics') for examining biomass composition, as for example lipid and carbohydrate content, is an elementary aspect of all biofuel projects. The fundamental objective is to employ cutting-edge analytical tools for the separation, detection, quantification and identification of biofuel-related compounds. This nationally unique, multi-platform analytical unit will provide advanced and complementary solutions for biofuel research in the AERI program.
• Virus-inspired metabolic engineering of lipid content in marine algae(Assaf Vardi)

  The world fossil oil reserves will be exhausted in less than 50 years. Therefore, renewable, carbon neutral, economically viable alternatives are urgently needed. The growing interest in microalgae for oil production is due to their relatively high lipid content and the new genetic and genomic resources that are currently available. We recently discovered that a marine algal virus has evolved unique metabolic strategies to infect its host by profoundly remodeling its lipid metabolism. Our overarching goal is to unfold some of the molecular secrets used during viral infection and mimic these metabolic principles to enhance lipid production for future biofuel application.

Thermoelectric Power Conversion (TE)

• Atomic and molecular thermoelectricity: the role of vibrations and noise in heat pump-ing and heat to electric power conversion(Oren Tal)

  Heat pumping and conversion of heat gradients to electric power (thermoelectricity) are fascinating schemes for sustainable energy. In particular, nanoscale conductors are attractive systems for such thermoelectric manipulations, due to their unique electronic and mechanical properties. However, it is not trivial to measure temperature at the nanoscale or control the parameters that promote thermoelectricity. We develop novel tools to probe the local temperature across metal-molecule-metal inter-faces (molecular junctions) to demonstrate heat-pumping and efficient thermoelectricity in unique structures of molecular junctions. We anticipate that this research will provide guidelines for efficient heat - electric power conversion.
   

Basic research for Biofuels

• Institute-wide consortium(A. Levy, Y. Eshed, A. Danon, U. Pick, E. Bayer, R. Milo, G. Galili, A. Aharoni, A. Vardi, N. Barkai, A. Scherz)

Solar Cells

• Molecules for Inverted Solar Cells(M. Van Der Boom)
• Defining Basic Performance Limitations of Molecule- based Solar Cells(M. Bendikov, G. Hodes, L. Kronik)

Optics

• Compact Solar concentrators with high concentration ratio(N. Davidson)
• New directions in sensitized quantum-dot based light Harvesting devices(D. Oron)

Collaborative Research Grants

• Organic nanocrystalline heterojunctions for robust solar cells(Boris Rybtchinski, Dan Oron)
• How does marine microbiology affect clouds and climate?(Assaf Vardi, Ilan Koren)
• Investigating the effects of Nutrient Limitation on the Isotope geochemistry and Microbial interactions in Blooms of Ocean algae - IN LIMBO(Itay Halevy, Einat Segev)

Single-lab Research Grants

• Developing a New Paradigm for Self-Repairing Materials(David Cahen, Igor Lubomirsky)
• Theory of defects and structural dynamics in chalcogenide perovskites for photovoltaic applications(Leeor Kronik)
• Hyperthermostable designer cellulosomes for enhanced conversion of cellulosic biomass en route to biofuels(Gideon Schreiber, Ed Bayer)
• The bulk photovoltaic effect in WS2 nanotubes(Reshef Tenne)
• An Iron-Molybdenum Molecular Capsule as a Functional Model for Nitrogenase Enzymes: The Electrocatalytic Reduction of Molecular Nitrogen to Ammonia with Water(Ronny Neumann)

Collaborative Research Grants

• Improving Materials’ Sustainability by Intrinsic Defect Healing(David Cahen, Dan Oron)

Single-lab Research Grants

• Sustainability and water: The disproportional effect of decreasing precipitation on ecosystem water-yield and its modification by vegetation(Dan Yakir)
• A method for recycling rare earth magnets(Igor Lubomirsky)
• Oxygenations with Molecular Oxygen by Unique and Novel Dioxygenase Pathways(Ronny Neumann)
• Computational design of high redox-potential enzymes for the utilisation or degradation of diverse anthropogenic pollutants(Sarel Fleishman)
• Electrochromic Metallo-Organic Assemblies for Generating Hydrogen by Water Electrolysis in Neutral Aqueous Solutions(Milko Van der Boom, Michal Lahav)
• Thermal energy harvesting with a structurally dynamic polymer gel(Ulyana Shimanovich)
• The potential role of coastal aquifers in the ocean carbonate system(Yael Kiro)
• Sustainable material farming(Filipe Natalio)

Single-lab Research Grants

• A method for recycling mixed rare earth/(Co+Ni) magnets(Igor Lubomirsky )
• Oxygenations with molecular oxygen by unique and novel dioxygenase pathways(Ronney Neumann)
• A cocktail of designed oxidoreductases for efficient lignocellulose biodegradation(Sarel Fleishman)
• Electrochromic metallo-organic assemblies for generating hydrogen by water electrolysis in neutral aqueous solutions(Milko van der Boom and Michal Lahav )
• Sustainability and water: The disproportional effect of decreasing precipitation on ecosystem water-yield and its modification by vegetation(Dan Yakir)
• Studying marine biofilms to mitigate the harmful effects of coastal slime formation(Einat Segev)
• Thermal energy harvesting by a polymer gel(Ulyana Shimanovich )
• The role of coastal aquifers in the ocean carbonate system(Yael Kiro)
• The dynamic and biochemical basis of material farming(Filipe Natalio)
• Contribution of transposable elements to rapid evolution and phenotypic variation in a wild wheat population(Avraham Levy)
• Sustainable composite plastics(Boris Rybtchinski )
• A new paradigm in solar concentrators(Nir Davidson)
• Low power event-based deep neural networks(Ehud Ahissar)
• Elucidating the structure of catalytic interfaces by selective NMR detection with endogenous dynamic nuclear polarization(Michal Leskes)
• Molecular mechanisms underlying the exceptional high light tolerance of Acacia species(Tamir Klein)
• The Effect of Ocean Acidification on the Formation of Molecular Crystals in Fish and Algae(Dvir Gur)

• Sponge diseases under climate change: addressing the role of the microbiome(Ziv Reich and Ruti Kapon )

Collaborative Research Grants

• Catching a CO2 valorisation reaction in action - Combining novel chemistry with novel techniques (Baran Eren & Sergey Semenov )
• Detecting long-distance anthropogenic effects on open-ocean microbes(Shira Raveh-Rubin & David Zeevi)

Photovoltaics and Thermoelectric Power Conversion (TE)

• Solar-pumped nanoscale quantum amplifier(Gershon Kurizki)

  Our goal is to design conceptually novel quantum nanometer-size amplifiers that may convert solar energy into useful work performed by photons or electrons with ultra-high efficiency. For photons this efficiency may approach 100%, above the conventional Carnot bound, because a quantum amplifier may achieve much better control of the conversion. Such designs may strongly boost the use of solar energy for diverse nanoscale applications because their predicted efficiency will make them highly attractive.

Photovoltaics

• Selective attachment of charge-extracting materials to perovskite layers: direct chemical bonding leading to strong and controllable electronic coupling in perovskite-based solar cells (Boris Rybtchinski, Gary Hodes)

  Perovskite solar cells show spectacular efficiencies (above 20%), low cost, and are prone to simple fabrication. However, the rational design of the interfaces between their most important components has not been achieved, hampering advancement of the field. Herein, we suggest a new strategy based on direct binding the active components of the perovskite solar cells, so that their interfacing and electronic properties can be controlled and enhanced resulting in a novel rational strategy that can ultimately result in improved solar cell performance and new types of perovskite solar cells.
• Dynamic disorder as a key to stability in lead-halide perovskites?(Leeor Kronik)

  Successful photovoltaic technology must combine high performance with low cost. Recently, hybrid organic-inorganic hybrid pervoskites (HOIPs), and especially methylammonium-leadiodide (MAPbI3), have drawn enormous attention because they combine the outstanding semiconducting properties of inorganic semiconductors with the generally lower costs of organic crystals. However, a major enigma is how a material synthesized using inexpensive techniques is even capable of achieving the high photovoltaic conversion efficiency that it does. Recently, it has become increasingly clear that HOIPs exhibit significant dynamic disorder, i.e., at least some of the atoms in the material exhibit major shifts from the equilibrium positions, even at room temperature and under standard operating conditions. Here, we wish to examine whether this “messy” and seemingly detrimental property is actually one of the keys to the success of this material. We propose to do so using first-principles calculations, based on the atomic species involved and the laws of quantum mechanics. In such calculations, static and dynamic structural and chemical motifs can be created in a controlled manner and their properties examined systematically. This should afford a detailed understanding of mechanisms allowing (and limiting) cell performance and stability and therefore allow us to point out strategies for making further progress.

Biofuel

• Duckweeds as a Platform for Biofuel and Sustainability(Avraham Levy and Asaph Aharoni)

  Duckweeds are tiny aquatic plants floating on still water that display rapid biomass proliferation.

  We propose to redesign its cell wall and its primary metabolism to turn it into an improved platform for bioethanol production and sustainability. This will be done combining expertise in transformation protocols (Edelman); genome editing methods (Levy); analytical chemistry and metabolism (Aharoni) and using the recently published duckweed’s full genome. Duckweed is highly effective in uptake of chemicals and heavy metals from water, enabling its use for waste water decontamination. These features make it a powerful system for sustainability.

Thermoelectric Power Conversion (TE)

• Thermoelectric Power Conversion (TE)Atomic and molecular thermoelectricity: the role of vibrations and noise in heat pumping and heat to electric power conversion(Oren Tal)

  Heat pumping and heat to electric power conversion are fascinating schemes for sustainable energy. Specifically, nanoscale conductors are attractive systems for such thermoelectric manipulations, due to their unique properties. However, it is not trivial to measure temperature at the nanoscale or control the parameters that promote thermoelectricity. We intend to develop noble tools for probing local temperature across metal-molecule-metal interfaces and demonstrate heat-pumping and efficient thermoelectricity in molecular-based structures. We aim to establish guidelines for efficient heat to electric power conversion. As the US manufacturing sector alone generates ~3000 TW/year of waste heat, the potential of thermoelectric conversion is huge.

Collaborative Research Grants

• Developing a Search Methodology for Self-Repair in Energy Materials(David Cahen, Dan Oron)

Single-lab Research Grants

• Thermal energy harvesting by a polymer gel(Ulyana Shimanovich)
• Development of sustainable food by emergent Lignocellulosic digestion in a host-microbiome system(Yoav Soen)
• Phage treatment for sustainable crop protection – overcoming bacterial immunity(Rotem Sorek)
• Linking Technology-Critical Elements in Leachate and a Value Creation Potential from Urban Mining(Brian Berkowitz)
• Molecular Level Understanding of Electrode Surfaces using Vibrational Spectroscopies under Electrochemical CO2 Reduction Conditions(Baran Eren)
• The Electrocatalytic Reduction of Molecular Nitrogen to Ammonia with Water(Ronny Neumann)

Collaborative Research Grants

• Organic nanocrystalline heterojunctions for robust solar cells(Boris Rybtchinski, Dan Oron)

  Perovskite solar cells have recently become the focus of a vast research effort because of their high efficiency (as high as 20%) that is achieved using low-cost constituents and solution processing. Yet, due to structural “softness,” thermal instability, and solubility in water, reproducible fabrication of the perovskite layers and the stability of perovskite solar cells represent key challenges.

  Prof. Rybtchinski and his group are addressing the fabrication challenge by studying the mechanisms of perovskite crystallization. They are tackling the stability challenge by using stable perovskite layers, as well as tailor-made new materials and creating new electrodes. They have shown how additives and surfaces influence perovskite crystallization, and used these discoveries to make better cells.

  Prof. Dan Oron and his team have studied the nucleation, growth, and structural transformations of perovskite crystals at the nano-scale. His group combines fundamental studies of the photophysics of semiconductor quantum dots adsorbed on surfaces with the creation of new designs for third-generation photovoltaic cells incorporating quantum dots.

  Together, their SAERI project zeroes in on understanding the dynamics of the interface between organic nanocrystals and thin films in order to create new classes of solar cells. In particular, the groups are studying CuPc-PDI (copper phthalocyanine / perylene diimide) interfaces, as their surface potential differences give rise to photovoltage upon illumination.

  The interfaces and fluorescence have been studied using Kelvin-probe force microscopy (KPFM), as well as time-resolved fluorescence and transient absorption studies. 

  The groups have identified several promising systems that will be further studied in depth and used for fabrication of high-performance organic solar cells.

   

• Two-level lasers as engines powered by ambient heat: From idea to experimental design(Nir Davidson, Gershon Kurizki)

  The experimental and theory partners are working together on the details  of the experimental scheme needed to demonstrate and study the concept of heat-driven engines in an atomic system. Prof. Kurizki conducts theoretical research in quantum optics and quantum thermodynamics, rapidly developing areas of physics that take advantage of the quantum properties of light and its interactions with matter. Experimentalist, Prof. Nir Davidson, has learned to manipulate atomic motion using lasers. However, most of Prof. Davidson’s work has been with ultracold atoms. The idea of creating a laser-powered heat engine requires exploring new dimensions.

   
• Can elevated CO2 compensate for climate change effects on forest sustainability?(Tamir Klein, Elisabetta Boaretto)

  Carbon dioxide concentrations have risen by more than 30% in the last 100 years as a result of fossil fuel burning and deforestation, and while there is concern that this can cause global climate change, plants that feed on CO₂ can take advantage of this rise and improve their water use efficiency and productivity. In doing so, forests slow down the rate of human-driven increase in atmospheric CO₂ concentrations, giving more time to reduce greenhouse gas emissions and prepare for climate changes. In the semi-arid zone, the CO₂ effect is especially strong—but it has been largely disregarded.

  Dr. Klein is one of a team of Weizmann environmental scientists who have shown that in dry regions, response to high CO₂ by trees is greater than in wetter regions, and results in reduced water loss through evapo-transpiration and, consequently, conservation of water, allowing trees to grow under increasingly dry conditions. These responses, the processes underlying them, and their implications for local eco-hydrology are complex and poorly understood at present.

  Prof. Boaretto’s archeological expertise and contacts have enabled the researchers to collect tree cores and meteorological data over the past 50 years in collaboration with experts in Uzbekistan. The samples are brought to the Weizmann Institute for analysis. Their goal is to better understand the longer term dynamics of climate change and its effects on the growth of forests.