Rearrangement of electroluminescence spectra in type-II $n$-InAs/$n$-InAsSbP heterostructures

Single heterostructures of type II $n^{+}$-InAs/$n^{0}$-InAs$_{0.59}$Sb$_{0.16}$P$_{0.25}$, based on an intentionally undoped epitaxial layer with an electronic type of conductivity are obtained by metalorganic vapor phase epitaxy (MOVPE). In the heterostructure, a transition layer of modulated composition is formed near the heterointerface in the bulk of the quaternary solid solution. The existence of a radiative recombination channel due to the presence of localized hole states in quantum wells formed in the transition layer near the heterointerface is shown. It is demonstrated that the maximum of the intensity of the electroluminescence spectrum of the heterostructure under study is rearranged when a forward external bias is applied. The results of this study can be used in the development of tunable light-emitting diodes operating in the midinfrared range of 2–4 $\mu$m.