Photovoltaic properties of silicon heterojunction solar cells fabricated on boron-doped silicon wafers under extraterrestrial illumination

Abstract

The temperature coefficient is a key performance indicator for assessing the operational stability of solar cells used for power generation in both terrestrial and space environments. In recent years, silicon heterojunction solar cells employing hydrogenated amorphous silicon passivating layers have attracted significant attention owing to their high conversion efficiency and excellent surface passivation quality achieved at low processing temperatures. However, to ensure their reliable and stable operation in extraterrestrial conditions, it is essential to investigate not only the effects of radiation but also the influence of temperature variations on their photovoltaic performance. In this study, the illuminated current–voltage characteristics of heterojunction solar cells fabricated on boron-doped single-crystalline silicon wafers were experimentally investigated under Air Mass Zero spectrum across a wide temperature range of 173–373 K. The results revealed that the short-circuit current density exhibited a positive temperature coefficient of +(0.077±0.003) %/K, whereas the open-circuit voltage decreased linearly with a coefficient of – (0.23±0.002) %/K as temperature increased. The temperature coefficients of the conversion efficiency and fill factor were determined to be – (0.23±0.007) %/K and – (0.075±0.004) %/K, respectively. The experimentally obtained temperature coefficient of the maximum output power – (0.231±0.008) %/K was found to be lower than that of conventional Al-BSF solar cells (−0.39%/K) and other single-crystalline silicon–based photovoltaic technologies, confirming the excellent thermal stability and high suitability of silicon heterojunction solar cells for space power applications.