Effects of contamination on solar cell coverglass

As the power generation capability of solar cells depends strongly on the spectra of the incident light through the coverglass, there is a critical need to understand the impact of adsorbed molecular (organic) contaminants, which absorb light in the short wavelength range. The goal of this work is to calculate solar cell current loss based on experimentally determined coverglass transmission change in the presence of contaminant films. Two representative contaminants, di-octyl phthalate (DOP) and DC704, were photo-fixed on the coverglass samples, which were subsequently irradiated with protons under a simulated 15-year GEO space radiation environment. The coverglass transmission change was characterized before and after each process. The coverglass transmission data were then convolved with the solar cell spectral response to determine the coverglass darkening effects on solar cell performance. The results indicate that the solar cell current could be significantly reduced due to the combined effects of contamination and proton exposure.