Acceleration and mitigation of carrier-induced degradation in p-type multi-crystalline silicon

Recently, a new carrier-induced defect has been reported in multi-crystalline silicon (mc-Si), and has been shown to be particularly detrimental to the performance of passivated emitter and rear contact (PERC) cells. Under normal conditions, this defect can take years to fully form. This Letter reports on the accelerated formation and subsequent passivation of this carrier-induced defect through the use of high illumination intensity and elevated temperatures resulting in passivation within minutes. The process was tested on industrial mc-Si PERC solar cells, where degradation after a 100 hour stability test was suppressed to only 0.1% absolute compared to 2.1% for non-treated cells. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)