Deep centers in a CuInGaSe2/CdS/ZnO:B solar cell

Abstract

CuInGaSe2(CIGS)/CdS/ZnO:B heterojunction solar cells and CIGS/Al Schottky junction diodes were fabricated, and the defect centers were examined by capacitancevoltage (CV) measurements and deep-level transient spectroscopy (DLTS). The homogeneity of the junction in the CIGS heterojunction solar cell was examined by electron-beam induced current (EBIC) measurements. The distribution of the defect concentrations in the CIGS absorber layer of the CIGS/CdS/ZnO:B heterojunction changed remarkably with depth. On the other hand, the defect distribution in the CIGS layer of the CIGS Schottky junction was quasi-homogeneous. One electron and one hole trap were observed from CIGS Schottky junction, whereas one electron trap and two hole traps were found in the CIGS/CdS/ZnO:B heterojunction.