Cu(In,Ga)Se-2 solar cells: Device stability based on chemical flexibility

Communication: Is "self-healing" the source of the stability of Cu(In, Ga)S e-2-based solar modules? The proven remarkable stability and radiation hard ness of Cu(In,Ga)Se-2 (CIGS) solar cells stand in apparent contradiction to the fact that CIGS shows both short-range (metastable defect centers) and long-range (significant Cu migration) instabilities. The authors suggest th at these instabilities may in fact be a prerequisite for CIGS's stability a s they allow a degree of flexibility or "smartness" in accommodating extern ally imposed changes. Two self-healing cycles are proposed, in which copper species play a particularly important role.