Admittance spectroscopy defect density of electrodeposited CuIn(S,Se)₂ and its correlation with solar cells performances

Abstract

Electrodeposited CuIn(S,Se)2 based solar cells with varying CdS buffer layer thicknesses were studied by admittance spectroscopy. An electrically active defect was identified. Its density of states which varies with CdS layer deposition process was found to be correlated with solar cell performance. This defect seems to be CdS/CuIn(S,Se)2 interface defect or to be located within the grain boundaries of the absorber layer. Direct dark I–V measurements reveal that the dominant recombination mechanism is a tunnelling assisted process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)