Illumination-dependent temperature coefficients of the electrical parameters of modern silicon solar cell architectures

Photovoltaic devices operate under a wide range of temperature and illumination conditions. While the temperature coefficients (TC) of crystalline silicon solar cells have been well-studied, there have been only a few investigations regarding the effect of illumination on TCs. In this study, the TCs of the main electrical parameters of various silicon solar cell technologies are first determined. The illumination spectrum dependence of the TC of the short-circuit current and the illumination intensity dependence of the TC of the open-circuit voltage are then investigated. For the latter investigation, a custom-designed temperature-dependent Suns-VOC system is used. It is found that: (1) the TC of the short-circuit current measured using an A-rated spectrum may differ from the TC measured using the AM1.5G spectrum by up to 30%, (2) the TC of the open-circuit voltage of all technologies at 0.001 suns approximately doubles compared to at one-sun, and (3) silicon heterojunction cells seem to have the overall best TC performance at medium to high intensities.