Numerical study of metal oxide hetero-junction solar cells with defects and interface states

• Published in: Semiconductor science and technology Vol. 28; no. 5; pp. 55004 - 55013
• Main Authors: Zhu, Le, Shao, Guosheng, Luo, J K
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 10.05.2013; Institute of Physics
• Subjects: Applied sciences; CuO; defects; Energy; Exact sciences and technology; heterojunction solar cells; interface states; Natural energy; oxide semiconductor; Photovoltaic conversion; Solar cells. Photoelectrochemical cells; Solar energy; TiO; Solar cell; Defect states; Defect density; Energy gap; Interface electron state; Performance; Heterostructures
• ISSN: 0268-1242; 1361-6641
• DOI: 10.1088/0268-1242/28/5/055004

Further to our previous work on ideal metal oxide (MO) hetero-junction solar cells, a systematic simulation has been carried out to investigate the effects of defects and interface states on the cells. Two structures of the window absorber (WA) and window absorber voltage-enhancer (WAV) were modelled with defect concentration, defect energy level, interface state (ISt) density and ISt energy level as parameters. The simulation showed that the defects in the window layer and the voltage-enhancer layer have very limited effects on the performance of the cells, but those in the absorption layer have profound effects on the cell performance. The interface states at the W A interface have a limited effect on the performance even for a density up to 1013 cm−2, while those at the A V interface cause the solar cell to deteriorate severely even at a low density of lower than 1 × 1011 cm−2. It also showed that the back surface field (BSF) induced by band gap off-set in the WAV structure loses its function when defects with a modest concentration exist in the absorption layer and does not improve the open voltage at all.