Research |

Halide and Sulfide Perovskites

To the surprise of many material scientists, about ten years ago, the halide perovskites emerged as excellent materials for solar cells. They are good because their excited charge carriers’ lifetimes are very long. Therefore, carriers can diffuse to the solar cell electrodes and create current. The long lifetimes were surprising because halide perovskites are soft, formed at low temperatures, and have many defects.

These materials’ unique electronic and optical properties ...

Organic Crystals

Organic semiconducting crystals have many applications in the (opto)electronic industry. Examples include light-emitting diodes (LED), field-effect transistors (FET), and solar cells.

Unlike inorganic semiconductors, where covalent or ionic bonds connect atoms, weak, Van der Waals intermolecular forces hold the organic semiconductors. The connection of the molecules by weak forces has a profound effect on the crystal's electronic and structural dynamics. We study the relationship between the motion of the molecules and the motion of the electrons inside the crystals.

Simulations and Collaborations with Theory Groups

Real, technologically relevant materials are incredibly complicated. Their complexity usually leaves them out of the reach of analytical methods. Fortunately, computational methods and the computing power to realize them have advanced far enough to calculate observable macroscopic material properties. These include dielectric response, thermal and transport properties, and the electronic and phononic band structures that engender them. This makes reliable simulations absolutely essential in contemporary materials science, as more often than not, general theories only offer a partial explanation, and the whole of the scientific story lurks in the specific details of the material and its thermodynamic circumstances.

Biomineralization

The mechanisms in which nature creates complex and diverse biominerals with different shapes, optical reflectivity, and mechanical and chemical properties is a fascinating field of study. The crystallization pathways are rapid yet controlled and can be utilized for biomimicry.

Oxide Perovskites and Ceramics

Oxide materials are of great interest to scientific and industrial communities due to the wide range of electronic and mechanical functionalities. Despite the strong bonds and high melting points, many oxides exhibit dynamic properties, such as piezoelectricity, electrostriction, or ionic conductivity, which originate from the complex motion of atoms upon external stimulation.