Light-induced-degradation defect independent of the boron concentration: Towards unifying admittance spectroscopy, photoluminescence and photoconductance lifetime spectroscopy results

Abstract

Recent photoluminescence and admittance spectroscopy measurements point towards the defect responsible for Light-Induced Degradation (LID) being a shallow level. Dopant dependent lifetime spectroscopy and temperature dependent lifetime spectroscopy on the other hand reveal the existence of a deep level driving the recombination activity of the LID defects. There is an apparent disagreement between admittance spectroscopy results and lifetime spectroscopy results. Here we overcome this apparent disagreement and we show that a negative-U defect with one shallow level can explain both the doping dependent lifetime data and injection dependent data. The critical consequence of this model is that it readily explains the dependence of the LID defect on the hole concentration rather than the Boron concentration.