Abstract:
High-voltage GaAs $p^+$–$p^0$–$i$–$n^0$–$n^+$-diodes, fabricated by liquid-phase epitaxy in a hydrogen environment, were studied before and after irradiation with neutrons with an energy of 1 MeV and a fluence of 2.9$\cdot$10$^{13}$ cm$^{-2}$. The main channels of recombination of minority carriers in the base $n^0$ layers of high-voltage GaAs diodes before and after neutron irradiation were determined using methods of deep-level transient spectroscopy and control of the dynamics of reverse recovery of diodes. The correspondence of the lifetime values of nonequilibrium charge carriers determined using both methods has been found. It was revealed that HL2 defects are the main recombination centers in diodes before irradiation, determining their dynamic characteristics and the lifetime of minority carriers in the lightly doped base layers. It has been established that after neutron irradiation, the dynamics of forward and reverse switching processes is determined by recombination through deep acceptor-like D$^-$ states of three-charged centers of radiation defect bands. It is found that in lightly doped GaAs layers, a damage defect surrounded by a large Coulomb barrier exhibits configurational metastability controlled by optical illumination.
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