Loss mechanisms in hydrazine-processed Cu2ZnSn(Se,S)4 solar cells

We present a device characterization study for hydrazine-processed kesterite Cu2ZnSn(Se,S)(4) (CZTSSe) solar cells with a focus on pinpointing the main loss mechanisms limiting device efficiency. Temperature-dependent study and time-resolved photoluminescence spectroscopy on these cells, in comparison to analogous studies on a reference Cu(In,Ga)(Se,S)(2) (CIGS) cell, reveal strong recombination loss at the CZTSSe/CdS interface, very low minority-carrier lifetimes, and high series resistance that diverges at low temperature. These findings help identify the key areas for improvement of these CZTSSe cells in the quest for a high-performance indium-and tellurium-free solar cell. (C) 2010 American Institute of Physics. [doi:10.1063/1.3522884]