Unveiling Auger recombination current component in rectification curves of silicon heterojunction solar cells

Abstract

The rectification characteristics of semiconductor junctions are the basis for their application in diverse electronic and optoelectronic devices. Theoretically, the manifestation of Auger recombination under high positive bias voltage enables solar cells to achieve a high fill factor (FF); however, other recombination mechanisms and high series resistance make it difficult to be observed in the rectification curve. Here, the Auger recombination current component is identified in the rectification curves of silicon heterojunction solar cells featuring high FF and high open-circuit voltage (Voc). The current–voltage (I–V) characteristics of the device with high-conductivity nanocrystalline silicon oxide emitter demonstrate a distinct diode component exhibiting an ideality factor of n = 2/3, which is a definitive indicator of Auger recombination. The temperature-dependent I–V characteristics and Suns-Voc measurements reveal that suppression of series resistance and defect-mediated recombination is essential for unveiling the Auger recombination component.