Deep-level transient spectroscopy analysis of proton-irradiated n+/p InGaP solar cells

Defects in p-InGaP produced by low-energy protons have beer) investigated by deep-level transient spectroscopy (DLTS). A new majority-carrier (hole) trap HPl has been observed in low-energy proton-irradiated p-InGaP at 0.90+/-0.05eV above the valance band for the first time. The HPl introduction rate for 100-keV proton-irradiated p-InGaP is 1500cm(-1), which is 6 times higher than that (260cm(-1)) for the 380-keV proton-irradiated one. Isochronal annealing is found to annihilate the proton-induced HPl defect above 300degreesC that is higher than the annealing stage (100degreesC) for 1-MeV electron-induced H2 center in p-InGaP. The carrier removal rates are found to be 61433 and 8640cm(-1) for 100 and 380-keV proton irradiation, respectively. Proton energy-dependent effects include decrease in both the carrier removal rate and in the defect introduction rate with increase in proton energy by creating HPl trap. (C) 2001 Elsevier Science B.V. All rights reserved.