Recovery After Potential-Induced Degradation of CuIn _ 1- x Ga ₓ Se ₂ Solar Cells With CdS and Zn(O,S) Buffer Layers

This study deals with potential-induced degradation (PID) of Cu(In,Ga)Se2-based solar cells and different approaches to subsequent recovery of efficiency. Three different recovery methods were studied: 1) etch recovery, 2) accelerated recovery, and 3) unaccelerated recovery. After being completely degraded, the solar cells with CdS buffer layers recovered their efficiencies at different rates, depending on the method which was used. On the other hand, if Zn(O,S) was used as a buffer layer instead of CdS, the recovery rate was close to zero. The buffer layer type clearly influenced the sodium distribution during PID stressing and recovery, as well as the possibilities for recovery of the electrical performance.