Analysis of Some Effects of Possible Device Degradation over a 30 Year Lifespan

An important issue for the crystalline Si wafer based PV industry is the performance of the cells over a life span of 25 to 30 years. The present paper discusses the main sources of degradation with focus on the diffusion of elements in a wafer over a 30-year period, which may result in semiconductor device degradation. Some experimental results of accelerated tests are presented. It has been shown that the variations of the performance of solar cells as manufactured vary considerably, and that a large statistical sample is necessary in order to obtain good conclusions from such experiments.