No abstract

A deep level transient spectroscopy study of native and radiation induced defects in metal organic chemical vapor deposition n on p 6H-SiC diodes has been conducted. Three majority carrier levels were found, at Ev+0.50, +0.55, and +0.69 eV, and three minority carrier deep levels were found, at Ec −0.38, −0.48, and −0.58 eV. These six levels were initially observed in the unirradiated materials. Their concentration increased 2 to 13-fold after irradiation to a fluence of 2×1011 cm−2 of 5.5 MeV alpha particles. In addition the carrier removal was monitored during irradiation, and a carrier removal rate of 7.8×104 cm−1 for 5.5 MeV alpha particles was measured. When compared with a similar study of alpha particle irradiation of InP, the results suggest that SiC has radiation resistance comparable to that of InP, another highly radiation resistant semiconductor.

No abstract

InP is a relatively radiation-resistant semiconductor and an attractive material for solar cells exposed to radiation in Earth orbit. To better understand this useful property of InP, proton irradiation induced defects in Zn and Cd doped InP have been studied by deep level transient spectroscopy. After 2 MeV proton irradiation the defects H3, H4, and H5 were observed in lightly Zn doped InP, while the defects H3 and H5 were observed in more heavily Zn and Cd doped InP. The concentrations of the irradiation induced defects were measured and the introduction rates were calculated and compared. The activation energies of the defects were measured and corrected for the effect of electric field on carrier emission. The capture cross sections of the defects were measured directly by the pulse width variation technique. The energy levels and capture cross sections of the defects were not affected by the substitution of Cd for Zn, but the introduction rate of the defect H5 was substantially lower in Cd doped InP, suggesting that this material would make an improved solar cell in a high radiation environment.

No abstract