Evaluation of diffusion-recombination parameters in electrodeposited CuIn(S, Se)2 solar cells by means of electron beam induced current experiments and modelling

Thin-film solar cells with a Cu-based chalcopyrite absorber achieve high conversion efficiencies (up to 20%). Their technology being more cost effective than the crystalline silicon technologies, they are expected to replace Si-based solar cells. But a best cost-performance ratio requires first a knowledge of the parameters which ascertain the electrical quality of the solar cell. The first of them is the minority carrier diffusion length in the absorber and the second one is the collection efficiency of the p–np–n junction space charge region (SCR) located within the absorber. A low value of at least one of them drastically reduces the efficiency of the cell. In this paper we present an electron-beam-induced-current (EBIC) determination of these two parameters in CIS solar cells.