Proposed new damp heat test standards for commercial CIGS modules with bias application or light irradiation

Abstract

Based on our results that conventional damp-heat (DDH) test on a commercial CCIGS (a.k.a. CCIS, CIGSS) module causes an irreversible "Test-specific" degradation (TSD) that is not observed in modules deployed in fields, we propose a new option for DDH testing of CIGS modules. We have tested full-size CIGS modules with/without forward bias, light irradiation and humidity during heat tests. The results clearly show that adding forward bias, or white light irradiation during DH tests suppresses this irreversible degradation. Based on these results, we have proposed to add forward bias and/or light irradiation during DH tests of CIGS modules, to make the test condition closer to real fields and suppress degradations not observed in the field.