The stability of MIS solar cells and evaluation by C-V characteristics

To test the stability of MIS solar cell structures, we investigated the I-V and C-V characteristics during tests under illumination and dark condition s. The MIS solar cells were prepared using two different techniques to prod uce two types of oxide layer. Under illumination, the tested devices suffer from degradation. The rate of degradation was higher for cells with a thin ner oxide layer. The cells with a thicker oxide layer exhibited a partial r ecovery for the open circuit voltage after storage in the dark. The degrada tion is due to the photo-neutralization of effective charges at the oxide-s emiconductor interface, This mechanism leads to instability in the cell per formance through changes in the barrier height. The C-V measurement confirm s this result. (C) 2001 Elsevier Science Ltd. All rights reserved.