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 NIn ≥ 1018 cm−3 decreases λ.

The electrophysical properties and cathode-luminescence(CL) spectra of p-type layers of GaAs〈Ge〉 with p=1.8·1017–3.6·1019 cm−3 obtained by the method of liquid-phase expitaxy for a Ge content in the solution of 0.4–12 at. % were investigated. Regularities are set up for the change in the Hall constant, the Hall hole mobility, and the CL spectra as a function of the impurity concentration and temperature, which are explained from the viewpoint of an impurity zone mode. On the basis of the data obtained it is assumed that the material properties studied are determined by the impurity centers GeAs and (GeGa-VGa).

The temperature dependence of the charge carrier concentration and mobility in n-type GaAs monocrystals doped jointly by Ge and isovalent In and Sb impurities is investigated. The observable charge carrier concentration and mobility changes in the GaAs:Ge:In and GaAs:Ge:Sb are compared with the corresponding characteristics in GaAs:Ge, and the change in properties along the ingots can be explained by the Ge impurity redistribution in the gallium and arsenic sublattices in the presence of an isovalent impurity.

The temperature dependences of the density, mobility, and lifetime of electrons, and the photoconductivity and cathodoluminescence spectra of gallium arsenide with different electron densities doped with germanium when single crystals are grown by the Czochralski method are investigated. An analysis of the scattering mechanism is given, and the acceptor and donor densities are determined. The acceptor-type capture levels are found from the temperature dependence of the electron lifetime. The results of a study of the cathodoluminescence spectra indicate the presence in the specimens of complex radiational recombination centers similar to germanium-atom complexes with inherent lattice defects.

An investigation was made into the electrical and photoelectric properties of gallium arsenide with an initial electron density 5×1015−4×1017 cm−3 doped with Mn in different thermodynamic diffusion regimes characterized by diffusion temperatures of 900 and 1000°C and arsenic vapor pressure 10−2 and 10−3 atm. The ionization energy and defect concentration were determined by a computer analysis of the equilibrium hole density determined from the Hall effect. Centers with ionization energy 0.08–0.10 eV were found, their concentration varying from 2×1019 to 2×1020 cm−3 depending on the diffusion temperature and the doping level of the original crystals. Data obtained by investigating the stationary intrinsic photoconductivity were used to determine a hole lifetime of tp 10−9 sec. The photoconductivity spectra were investigated in the range 0.5–2 eV at 77°K, and defects with ionization energy Ev + 0.6 eV were found in all samples. The impurity photoconductivity at wavelength 10.6 μm was investigated. It was shown that GaAs∶Mn can be used as a material for impurity photoresistors.

Investigations were made of the electrical properties, the cathodolumiescence and photoconductivity spectra, and the temperature dependence of the majority carrier lifetime in gallium arsenide with a high concentration of tin (n=2·1018 cm−3, 1.5·1017 cm−3) that was doped with copper under different diffusion regimes. Measurements of the Hall effect revealed centers with an ionization energy 0.175 ± 0.005 eV, their concentration depending on the rate of cooling of the samples. The cathodoluminescence and Hall effect data suggest that the cathodoluminescence band observed at 1.35 eV in GaAs∶Sn∶Cu is associated with radiative transitions of electrons to centers with ε a =Ev + 0.175 eV. The hole lifetime in GaAs∶Sn∶Cu has a complicated temperature dependence which can be explained qualitatively by the presence of two types of capture center.

The distribution of the electrophysical and photoelectric properties of diffuse layers of p-GaAs obtained by doping copper using different diffusion modes is investigated. The properties of diffuse layers of p — n structures and volume specimens doped with copper over the whole depth are compared. The behavior of impurity centers is studied in these specimens and their effect on the electrophysical and photoelectric parameters of the material is investigated.

Certain regularities are established which permit tracing the influence of the second level on the results of computing impurity center parameters by means of the results of an analysis of the log p(1/T) curve by using a “one-level” model. It is shown that the value of the impurity center degeneration factor can be the criterion for correspondence between the model selected and the true energy spectrum of the semiconductor.

The properties of gallium arsenide doped with copper are investigated for different modes of diffusion, as a material for the sensitive elements of a photoresistor IR receiver. The procedure for obtaining specimens with the required parameters is established, and the material obtained is used to manufacture photoresistors. The threshold sensitivity Pt of a photoresistor receiver with microwave bias based on gallium arsenide doped with copper reaches the values obtained in photoreceivers based on germanium doped with gold, but the GaAs:Cu photoreceiver has a more rapid response. The detection capability D*of a GaAs:Cu photoresistor receiver with microwave bias considerably exceeds the values of D* of a photoreceiver with a constant bias using the same material.

The electrical conductivity, Hall effect, ionization energy, and defect concentration of GaAs samples subjected to various forms of heat treatment were studied. The original material comprised single crystals grown by the Bridgman and Czochralski methods with electron concentrations of 2·1015−7·1017 cm−3. The ionization energy and defect concentration were calculated with an electronic computer. The thermal conversion of GaAs was attributed to traces of copper, lattice defects, and residual impurities. The mobility varied in a complicated manner with the temperature of heat treatment in GaAs samples retaining their original n-type conductivity.