Dependence of displacement threshold energy on materials in compound-semiconductor of InP-type

Okuno, Yasuki; Imaizumi, Mitsuru*

In the theory of irradiation damage, a primary knock-on-atoms is considered to be generated, if the transferred energy (ET) given to the atom from the radiation by the interaction is larger than displacement threshold energy (Ed). A value of Ed has been conventionally determined by elements, without considering material dependency. In previous research, it was suggested that the Ed of each P in InGaP solar cell was 4 eV instead of 9 eV that has been used in the method of radiation degradation prediction of space solar cell. Additionally, the Ed of P in InP has been calculated to be 7.7 eV in the report by A. Sibille et al.. In the theory of radiation damage, the factor that determines Ed is considered to be a binding energy (EB) and a jumping energy (EJ). The EB value of P in InP and InGaP is calculated as cohesive energy by the first principles calculation based on density functional theory. In the results, it was suggested that EB has no correlation with the Ed value, and has little effect on the one.