Impact of the Number of Quantum Wells on the Photoluminescence of GaAsBi Multiple Quantum Wells

We present detailed low- and room-temperature photoluminescence analysis of GaAsBi/GaAs multiple-quantum well structures containing between 3 and 63 quantum wells of nominal 8-nm thickness, emitting at 1.1–1.3 eV. Pump-power-dependent measurements of the samples are compared with measurements of single GaAsBi/GaAs quantum wells from the literature. We find that the seemingly disparate results from the literature, including full width at half maximum values ranging from 35 meV to 130 meV, can be reconciled by considering electronic state filling in the material. We see sequential Bi-induced localized state-filling, and quantum well ground and excited state contributions, which are sometimes obscured by sample heating during the measurement. Sample-specific photoluminescence features are related to results from complementary structural characterization. Alongside reconciling seemingly disparate results from the literature, this work shows that many-quantum well stacks can exhibit luminescence linewidths comparable to single GaAsBi quantum wells and bulk samples from the literature.