Time/Temperature Degradation of Solar Cells under the Single Diode Model

This paper presents an extensive analysis of the degradation of solar cells due to time and temperature. This analysis is based on the single diode model (SDM) and relies on HSPICE to initially establish through simulation the relationships between model parameters, efficiency and process variations. The analysis is extended to the operational temperature and time by extracting the degradation in the performance of the solar cell. The result shows that the efficiency of solar cells has an inverse relationship with temperature (i.e. at high temperature the efficiency degrades), irradiance levels are affected by the change of the photo-generation current and the series resistance in the single diode model. Moreover, when time is considered (at a fixed temperature), the resulting degradation is analyzed by extraction and optimization of the SDM parameters, in this case, every parameter decreases linearly except the diode saturation current and the diode ideality factor that increase by polynomial and linear relationships, respectively.