The search for semiconducting materials with improved optical properties relies on the possibility to manipulate the semiconductors band structure by using quantum confinement, strain effects, and by the addition of diluted amounts of impurity elements such as $\mathrm{Bi}$. In this study, we explore the possibility to engineer the structural and physical properties of the $\mathrm{Ga}(\mathrm{As},\mathrm{Bi})$ alloy by employing different stress conditions in its epitaxial growth. Films with variable concentration of $\mathrm{Bi}$ are grown by molecular beam epitaxy on bare $\mathrm{Ga}\mathrm{As}(001)$ crystals and on partially relaxed $(\mathrm{In},\mathrm{Ga})\mathrm{As}$ double buffer layers acting as stressors aiming to control the $\mathrm{Bi}$ incorporation into the alloy and improving the optical properties in terms of efficiency. A combination of several structural and electronic characterization techniques and dedicated density-functional-theory calculations allows us a systematic comparison between the samples grown under compressive and tensile strain. We demonstrate the possibility to grow $\mathrm{Ga}(\mathrm{As},\mathrm{Bi})$ under different strain conditions without affecting its crystal quality. The different strain conditions strongly impact the $\mathrm{Bi}$ incorporation in the $\mathrm{Ga}\mathrm{As}$ matrix and the luminescence properties of the sample. We find (i) a striking improvement of the photoluminescence with a strongly increased radiative efficiency when $\mathrm{Ga}(\mathrm{As},\mathrm{Bi})$ is grown under tensile strain and (ii) an interesting higher redshift with respect to $\mathrm{Ga}(\mathrm{As},\mathrm{Bi})$ grown compressively on $\mathrm{Ga}\mathrm{As}$. These two effects allow us to reach the important photoluminescence emission at 1.3 µm with a $\mathrm{Bi}$ concentration as low as 4.9% compared to 7.5% needed for samples grown directly on $\mathrm{Ga}\mathrm{As}$. This is a significant achievement for the application of the $\mathrm{Ga}(\mathrm{As},\mathrm{Bi})$ material in optoelectronic devices.

• Received 18 March 2020
• Revised 22 May 2020
• Accepted 22 May 2020

DOI:https://doi.org/10.1103/PhysRevApplied.14.014028