Effect of Electron Irradiation on Electrical and Electroluminescent Properties of n~+p 4H-SiC Structures

摘要

A study of how electron irradiation affects the current-voltage (I-V) and electroluminescence (EL) characteristics of two types of 4H-SiC n~+p structures with p-base and base doping to -5-10~(15) cm~(-3) is presented. The characteristics were measured prior to irradiation and after each of five stages of irradiation with 0.9 MeV electrons at doses in the range from 1?10~(15) to 1.1?10~(16) cm~(-2). The irradiation leads to an increase in the recombination current, decrease in the intensity of the edge EL (hv_(max)~3.18 eV), and increase in the intensity of the infra-red (IR) EL (hv_(max)~1.35 eV), which starts to predominate. Presumably, this indicates that the nonequilibrium carrier lifetime decreases and the concentration of acceptor type defects grows as a result of the irradiation. The IR EL, attributed to a complex defect containing a silicon vacancy, is of interest for development of single-photon sources of light.