Misfit dislocation–related deep levels in InGaAs/GaAs and GaAsSb/GaAs p–i–n heterostructures and the effect of these on the relaxation time of nonequilibrium carriers.

A study of deep levels in InGaAs/GaAs and GaAsSb/GaAs <italic>p0–i–n</italic>0 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 <italic>p-i-n</italic> diodes is reported. Experimental capacitance–voltage characteristics and deep-level transient spectroscopy spectra of <italic>p+–p0–i–n0–n+</italic> 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 <italic>p0</italic> and <italic>n</italic>0 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 <italic>p-i-n</italic> diodes, are dislocation-related hole traps that are similar to HD3 and have the following parameters: thermal activation energy <italic>Et</italic> = 845 meV, carrier capture cross-section <italic>σp</italic> = 1.33 × 10−12 cm2, concentration <italic>Nt</italic> = 3.80 × 1014 cm−3 for InGaAs/GaAs and <italic>Et</italic> = 848 meV, <italic>σp</italic> = 2.73 × 10−12 cm2, and <italic>Nt</italic> = 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 <italic>p-i-n</italic> diodes. [ABSTRACT FROM AUTHOR]