We focus on the following research areas
1. Fundamental physics and chemistry of point defects in III-V and II-VI semiconductors
Binary semiconductors such as arsenides, nitrides, and oxides are technologically important for many applications such as optoelectronics and photovoltaic. A main goal of this project is to understand the impact of point defects and impurities on the electrical and optical properties of novel semiconductors from First-principles calculations.
2. n-type and p-type doping in wide-band gap semiconductors
Doping is an approach to enhance the number of carriers in semiconductors. While p-type and n-type doping in conventional semiconductors such as Silicon or GaAs is well established, doping in wide-band gap materials such as ZnO, In2O3, SrTiO3 is much less explored. Moreover, the physics of n-type and p-type in wide-band gap semiconductors are not well understood yet.
3. Probing local structure of defects and materials
By using first-principles density functional calculations, we can identify the defects structures in materials by comparing with other relevant experimental results. For example we can directly compare our computational results to the X-ray absorption spectroscopy (XAS) or infrared (IR) absorption spectroscopy. This can help us to understand the physical properties in materials influenced by the defects and we can control or change the physical properties into the desired way by controlling the formation of defects in materials.
4. Materials for solar energy conversion and photocatalysis
Advanced density-functional calculations allow us to theoretically design the properties of materials for solar energy conversion such as photovoltaics and photocatalysis which are required for sustainable development. A big issue on this area is how to engineer the band gap of materials to be response for the major portion of solar spectrum, visible light. The insight into the behavior of native defects and impurities that can be incorporated during synthesis is also required. An application of photocatalysis is water splitting for H2 production.
5. Nano-materials for sustainable and green environment
Two-dimension materials including porous graphene, boron nitride, C2N and other low-dimension compounds are promising for hydrogen storage and gas purification. Our aim is to explore the possibility and pave a way for improving the properties by chemical or mechanical tailoring these materials. DFT calculations are powerful tools for these purposes.