Speaker: Zhen-Hai Wang

Beijing Computational Science Research Center    

Abstract: Radially modulated (core/shell) heterostructured nanowires (NWs) have been explored extensively as photovoltaic (PV) materials to produce high-efficiency, robust, integrated PV power sources at low cost. In this talk, I will present our first-principles study on the ZnO-GaN heterostructures under density functional theory (DFT) framework. The band alignments of them have been revealed by different exchange-correlation functional methods. Our calculations show that ZnO-core/GaN-shell NWs rather than GaN-core/ZnO-shell ones are predicted to exhibit natural charge spatial separation behaviors, which are understandable in terms of an effective mass model. Furthermore, ZnO-GaN solid solution, (Ga1-xZnx)(N1-xOx) followed type-II band alignment with the host materials, has been introduced into GaN/ZnO core/shell solar cell model to improve the visible light absorption ability and carrier collection efficiency. 

Date&Time: November 16, 2012 (Friday), 14:30–15:30
Location: 606 Conference Room