Numerical analysis of CZTS/n-Si solar cells using SCAPS-1D. A comparative study between experimental and calculated outputs
CZTS (Cu2ZnSnS4) is a p-type semiconductor material which has been intensively used as an absorbing layer for thin film solar cells. Using pulsed laser ablation + deposition technique, we have been able to successfully form a CZTS/n-Si heterojunction solar cells with an optimum thickness of 210 nm of CZTS thin film. Different characteristics (optic, crystal and morphologic) of CZTS thin films have been investigated according to the thickness of CZTS thin film. We have accomplished a simulation work based on CZTS/c-Si hetero junction solar cells using SCAPS-1D. Into this model, experimental data including band gap, thickness and absorption coefficient have been introduced. The change of hole carrier's density in CZTS thin film, interface defect density in CZTS/n-Si hetero junction and device temperature have been found to be very influential on J-V characteristics of a CZTS (210 nm)/c-Si solar cell. SCAPS-1D model has also been introduced for the other three different CZTS thin films thicknesses and the results obtained from both SCAPS-1D program and experimental measurements have been found to be very close to each other.