Photoluminescence of electron-and neutron-irradiated n-type 6H-SiC

Abstract

n-type 6H-SiC materials irradiated with electrons having energies of Ee=1.7, 0.5, and 0.4 MeV and neutrons are studied via low temperature photoluminescence. For Ee ≥ 0.5 MeV electron-irradiated and neutron-irradiated samples, the LTPL emission lines S1/S2/S3 at 478.6/483.3/486. lnm are observed for the first time. Thermal annealing studies show that the defects S1/S2/S3 disappear at 500°C. However, the well-known D1-center is only detected for annealing temperatures over 700°C. By considering the threshold displacement energies of Emin(C) and Emin(Si) and thermal annealing behavior, it is found that the defects S1/S2/S3 are a set of silicon-related primary defects and the D1-center is a kind of secondary defect.