Optimization of precursor deposition for evaporated Cu2ZnSnS4 solar cells

The influence of three kinds of precursor depositions on the performance of corresponding Cu 2 ZnSnS 4 solar cells has been investigated, which includes evaporation of stacking metal layers (Mo/Zn/Cu/Sn), co-evaporation of metal elements (Mo/(Zn,Cu,Sn)) and co-evaporation of metals together with a small amount of sulfur (Mo/(Zn,Cu,Sn,S)) . It is found that Mo/(Zn,Cu,Sn) leads to large grain absorber and the best open circuit voltage V OC , short circuit current density J SC and efficiency; Mo/Zn/Cu/Sn produces a porous structure with small grain size which causes lowest shunt resistance, V OC , J SC and efficiency; Mo/(Zn,Cu,Sn,S) results in a dense film with small grain size which induces highest shunt resistance (R SH ) and fill factor (FF); ~200 nm thick MoS 2 layer is formed during the sulfurization.