On the impact of barrier-layer doping on the photoluminescence efficiency of InGaAlAs/InGaAs/InP strained-layer heterostructures

The photoluminescence of strained InGaAlAs/InGaAs/InP heterostructures with an active region consisting of nine In$_{0.74}$Ga$_{0.26}$As quantum wells and $\delta$-doped In$_{0.53}$Al$_{0.20}$Ga$_{0.27}$As barrier layers grown by molecular beam epitaxy on an InP(100) substrate is investigated. Analysis of the photoluminescence spectra demonstrates that $p$-type doping leads to an increase in the photoluminescence efficiency at low excitation levels in comparison to a heterostructure with undoped barriers, and increasing the level of barrier doping to (1–2) $\times$ 10$^{12}$ cm$^{-2}$ results in the suppression of nonradiative recombination.