Effect of electron irradiation on the electrophysical properties and photoluminescence of nuclear-transmutation-doped gallium arsenide

Abstract

The Hall effect, the electric conductivity, and the photoluminescence spectra of electron irradiated (E=1 MeV, D=1.1·10¹⁵−3.8·10¹⁸ cm⁻²) nuclear-transmutation-doped n-GaAs crystals and crystals of n-GaAs doped by the standard metallurgical method were investigated. The energy spectrum of the radiation-induced defects, determined from the Hall effect and DLTS spectra [E1–E5 traps with ionization energy 0.08, 0.14, 0.31, 0.71, and 0.9 eV, respectively (from the bottom of the C band)], is the same in nuclear-transmutation-doped and standard GaAs and satisfactorily describes the experimental dependence n(D). The rate of introduction of traps E1, E2 decreases as n₀ increases (from 1.3 cm⁻¹ in GaAs with n₀ — 10¹⁷ cm⁻³ to 0.7 cm⁻¹ in GaAs with n₀ ≃ 10¹⁸ cm⁻³). The rate of removal of charge carriers (λ) increases as n₀ increases, irrespective of the method of growth and doping of GaAs. The isovalent impurity In in nuclear-transmutation-doped gallium arsenide with N_In ≥ 10¹⁸ cm⁻³ decreases λ.