ABSTRACT
Electroluminescence (EL) in a type II broken-gap p-GaInAsSb/p-InAs single heterojunction has been studied at T = 4.2 K under magnetic fields as high as 4.6 T. Two EL bands with energies in maximum 311 meV (band A) and 384 meV (band B) observed at T = 77 K shift towards higher energies as temperature is lowered to 4.2 K, the short-wave band splitting into two subbands (B1 and B2). Bands B1 and B2 shift towards higher energies with increasing magnetic field. The intensity of the high energy sub-band oscillates under magnetic field. Time-resolved spectroscopy estimates the time constant corresponding to non-equilibrium carrier relaxation to be about 10 µs. The results are discussed in the framework of a model taking into account band-to-acceptor recombination in InAs as well as tunnelling radiative recombination of electrons and holes localized in the adjacent wells at both sides of the heterojunction.
