Device characteristics of high performance Cu2ZnSnS4 solar cell

Recently we reported a record efficiency of 8.4% for Cu₂ZnSnS₄ (CZTS) solar cell made by vacuum process [1]. We present a more comprehensive characterization of this CZTS cell employing various techniques such as temperature dependent I-V and biased quantum efficiency. By comparing the cell with the data from a reference champion CdTe cell that has similar bandgap, we identify that the biggest problem is the V_OC deficit followed by J_SC deficit and low fill factor issue. We present analyses of various characterization results to elucidate the underlying factors in the performance bottleneck issues in this present generation of CZTS cell.