Stabilizing CdTe/CdS solar cells with Cu-containing contacts to p-CdTe

High efficiency CdTe/CdS thin-film solar cells require low resistance conta cts to p-CdTe, which is frequently achieved by addition of Cu. Decreases in cell efficiency over time. however. have been associated with Cu from the contact. The question that is considered here is if Cu is really detrimenta l to cell performance? By performing a series of thermal stress tests the a uthors reach a far more optimistic conclusion than what has hitherto been a ssumed. The Figure shows the proposed model for action of Cu (and Cl) in th e CdTe/CdS cell.