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 μm, whereas short-circuit current, and thereby efficiency, saturates (98 % of max) at >1.1 μm 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 μm due to back contact recombination.