Explanation for carrier removal and type conversion in irradiated silicon solar cells

Heavy doses of radiation in space can cause the failure of $n+/p/p+$ silicon solar cells due to the gradual introduction of compensating defects into the base layer of the diode. In this letter, we show that the radiation-induced defects, which play the most important role in this process, referred to as “carrier removal,” are probably minority-carrier traps at an energy level approximately 0.18 eV below the conduction band. We conclude that these defects must be positively charged before electron capture, and therefore, act as donor centers which compensate the $p$-type base layer.