Epitaxial growth of GaAsBi on thin step-graded InGaAs buffer layers. (1st June 2022)

• Record Type: Journal Article
• Authors: Paulauskas, T; Devenson, J; Stanionytė, S; Skapas, M; Karpus, V; Čechavičius, B; Tumėnas, S; Strazdienė, V; Šebeka, B; Pačebutas, V
• Is Part Of: Semiconductor science and technology. Volume 37:Number 6(2022)
• Publication Date: 2022-06-01
• Subjects: GaAsBi -- molecular beam epitaxy -- InGaAs buffer -- valence band splitting; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1361-6641/ac61ff
• Languages: English
• ISSNs: 0268-1242

Abstract

Abstract: Molecular beam epitaxy growth and analysis of GaAsBi on compositional step-graded InGaAs buffer layers are presented in this study. The developed buffer is only 240 nm thick, exhibits very low surface roughness while reaching up to 0.46% lattice-mismatch with a GaAs substrate. Reciprocal-space mappings showed that 500 nm thick GaAsBi layers with 2.7%–5.3% Bi remain pseudomorphic with the InGaAs buffer, in contrast to GaAsBi grown on GaAs that were found to incur up to 50% lattice relaxation. CuPtB -type ordering and associated polarized photoluminescence were also found in the bismide layers grown on the InGaAs buffers. Optical anisotropy of a strain-free 2.7% Bi GaAsBi was further analysed by a suite of optical techniques indicating that the valence band splitting is ∼40 meV. This study advances synthesis techniques of thick GaAsBi layers for optoelectronic device applications.