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The variation of the effective lifetime of minority carrier lifetime τeff with temperature has been studied in the temperature range 300–580 K in AlxGa1−xAs base regions of p+–p0–i–n0–n+ high-voltage GaAs–AlGaAs diodes grown by liquid-phase epitaxy. It was found by using deep level transient spectroscopy that the emission/capture of electrons and holes in AlxGa1−xAs p0–i–n0 epitaxial layers is governed by the DX− states of the DX center formed by Se/Te background impurities. The Arrhenius plots associated with the τeff were used to determine the activation energy of the hole capture to the DX− level to be Ec = 159 meV. It is shown that the thermal capture of holes to the DX− level determines the relaxation time of nonequilibrium carriers in the AlxGa1−xAs base layers as well as its temperature dependence. [ABSTRACT FROM AUTHOR]

A study of deep levels in InGaAs/GaAs and GaAsSb/GaAs p0–i–n0 heterostructures with misfit dislocations and identification of the effective defects responsible for the significant (by up to a factor of 100) decrease in the relaxation time of nonequilibrium carriers in the base layers (and in the related reverse recovery time) of InGaAs/GaAs and GaAsSb/GaAs high-voltage power p-i-n diodes is reported. Experimental capacitance–voltage characteristics and deep-level transient spectroscopy spectra of p+–p0–i–n0–n+ homostructures based on undoped GaAs layers without misfit dislocations and InGaAs/GaAs and GaAsSb/GaAs heterostructures with a homogeneous network of misfit dislocations, all grown by liquid-phase epitaxy, are analyzed. Acceptor defects with deep levels HL2 and HL5 are identified in GaAs epitaxial p0 and n0 layers. Dislocation-related electron and hole deep traps designated as ED1 and HD3 are detected in InGaAs/GaAs and GaAsSb/GaAs heterostructures. The effective recombination centers in the heterostructure layers, to which we attribute the substantial decrease in the relaxation time of nonequilibrium carriers in the base layers of p-i-n diodes, are dislocation-related hole traps that are similar to HD3 and have the following parameters: thermal activation energy Et = 845 meV, carrier capture cross-section σp = 1.33 × 10−12 cm2, concentration Nt = 3.80 × 1014 cm−3 for InGaAs/GaAs and Et = 848 meV, σp = 2.73 × 10−12 cm2, and Nt = 2.40 × 1014 cm−3 for the GaAsSb/GaAs heterostructure. The relaxation time of the concentration of nonequilibrium carriers in the presence of dislocation-related deep acceptor traps similar to HD3 was estimated to be 1.1 × 10−10 and 8.5 × 10−11 s for, respectively, the InGaAs/GaAs and GaAsSb/GaAs heterostructures and 8.9 × 10−7 s for the GaAs homostructure. These data correspond to the relaxation times of nonequilibrium carriers in the base layers of GaAs, InGaAs/GaAs, and GaAsSb/GaAs high-voltage power p-i-n diodes. [ABSTRACT FROM AUTHOR]