CZTS Solar Cell Device Simulations with Varying Absorber Thickness

In this study the influence of absorber layer thickness on the trends of the four current-voltage (J-V) parameters for our CZTS solar cells is studied with simulations and compared with empirical data. In the case of dominating interface recombination we find that open-circuit voltage and fill-factor are largely unaffected by thickness variations 0.5-2.0 mu m, whereas short-circuit current, and thereby efficiency, saturates (98 % of max) at > 1.1 mu m absorber thickness, in agreement with measurements. In the case of suppressed interface recombination all four J-V parameters exhibit strong thickness dependence at <0.5 mu m due to back contact recombination.