It was noted that minority carrier injection annealing under forward-bias conditions enhanced defect annealing in InGaP and resulted in the recovery of solar-cell properties. This anomalous recovery, of properties affected by radiation damage, demonstrated that InGaP-based devices - under minority-carrier injection-mode operation – could exhibit a superior radiation resistance when compared with GaAs and Si. The first example of a recombination-enhanced mechanism in this ternary compound was also noted. Detailed studies were made of the stability of the radiation-induced defect, H2, in p-InGaP under various biases in order to determine the dependence of the reaction rate upon the position of the Fermi level in the absence of minority carrier injection and recombination. Recombination-enhanced defect annealing of H2 caused a reduction in the minority carrier injection annealing activation energy, as compared to thermal annealing, from

1.69 to 0.52eV. An analysis of the results revealed that the mechanism involved in minority carrier injection annealing of the defect was the energy release mechanism; in which enhancement was induced by the energy that was released when a minority carrier was trapped at the defect site.

Deep Level Transient Spectroscopy Analysis of 10MeV Proton and 1MeV Electron Irradiation-Induced Defects in p-InGaP and InGaP-Based Solar Cells. A.Khan, M.Yamaguchi, N.Dharmaso, J.Bourgoin, K.Ando, T.Takamoto: Japanese Journal of Applied Physics - 1, 2002, 41[3A], 1241-6