We present here the direct observation of the majority and minority carrier defects generation from wide-band-gap (2.04eV) and thick (2μm) p-AlInGaP diodes and solar cells structures before and after 1MeV electron irradiation by deep level transient spectroscopy (DLTS). One dominant hole-emitting trap H1 (EV+0.37±0.05eV) and two electron-emitting traps, E1 (EC−0.22±0.04eV) and E3 (EC−0.78±0.05eV) have been observed in the temperature range, which we could scan by DLTS. Detailed analysis of the minority carrier injection annealing experiment reveals that the H1 center has shown the same annealing characteristics, which has been previously observed in all phosphide-based materials such as InP, InGaP, and InGaAsP. The annealing property of the radiation-induced defects in p-AlInGaP reveals that multijunction solar cells and other optoelectronic devices such as light-emitting diodes based on this material could be considerably better to Si and GaAs in a radiation environment.

An investigation of electronhole emission from chemical beam epitaxy grown InAsPdlnP multiquantum well solar cell structures has been cartied out. Detailed analysis of double deep level transient spectroscopy shows that traps El, E2, E2, and E4 are extended over the whole multiquantum well region including interfaces. The trap E3 exhibits strong field dependence and having large capture cross section, which might acts as a strong recombination center. The field dependence of E3, indicates lowering of the emission barrier and an enhancement of the emission mates by the applied electric field.

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