In-situ analysis of the degradation of Cu(In, Ga)Se2 solar cells

A unique method has been developed to in-situ monitor the accelerated degradation in Cu(In, Ga)Se₂ solar cells, in which a degradation setup uses humidity, high temperatures and illumination as loads. IV characteristics of the solar cells are collected during the degradation. Cu(In, Ga)Se₂ solar cells and minimodules were degraded in the set-up and analyzed. We report on the formation of spots on the cell surface and indicate modifications in the i-ZnO/CdS region that result in changes in the external quantum efficiency. Furthermore, an increase in series resistance and a decrease current density was measured.