Effect of electron irradiation on the properties of germanium-doped gallium arsenide

Abstract

The Hall effect, electrical conductivity (77–370 K), and photoluminescence spectra (77 K) are studied in single-crystals of nuclearly doped GaAs (NDG) and GaAs doped with Ge by the metallurgical method after irradiation by electrons (E= 1 MeV, D=1.1·10¹⁵–3.8·10¹⁸ cm⁻²). Initial electron concentrations were n= 1.7·10¹⁷ cm⁻³ and n₀=2.6·10¹⁷ cm⁻³ respectively. In the GaAs doped during crystal growth by the Czochralski method the degree of compensation related to the amphoteric impurity Ge is higher (K=0.8) than in the NDG (K=0.4) for identical initial electron concentration. It was established that the rate of charge carrier removal in GaAs<Ge> is lower than in NDG, while radiation defects are more thermostable in NDG. The energy spectrum of radiation defects and radiating recombination centers, and the basic steps in reestablishment of electrophysical and optical properties in GaAs<Ge> and NDG are similar, i.e., they do not depend on the method of germanium doping.