EXPERIMENTAL-MODEL AND LONG-TERM PREDICTION OF PHOTOVOLTAIC CONVERSION EFFICIENCY OF A-SI SOLAR-CELLS

Degradation and recovery tests have been conducted on recent single-ju nction a-Si solar cells under various light intensities and temperatur e conditions to predict long-term stability. Saturation phenomena of t he degradation of efficiency have been shown experimentally. The degra dation characteristics are expressed as the second extreme distributio n function of the largest value with saturation introduced. The depend ence of saturation on the cell temperature and the light intensity are investigated. The worst efficiency of seasonal changes over a long te rm can be predicted from the saturation characteristics.