Numerical Analysis of Water Ingress Effect on the Window Layer of Cu(In,Ga)Se 2 Solar Cells using SCAPS-1D

CIGS solar cells were submitted to damp heat treatment of the window layer by immerging the full devices into deionized water at 50°C for 24 hours. An overall loss in device performance was observed by current-voltage (J-V) measurements after such exposure, mostly due to a decrease in short-circuit current density, open-circuit voltage, and fill factor. To determine the underlying cause of device degradation, the devices parameters were numerically simulated using SCAPS-1D, in correlation with other materials characterization such as secondary ion mass spectrometry. The device modifications were best simulated by a change in transmission coefficient, total trap density and trap density peak position.