Progress Toward III–V Bismide Alloys for Near- and Midinfrared Laser Diodes

Abstract

Bismuth-containing III–V alloys open-up a range of possibilities for practical applications in semiconductor lasers, photovoltaics, spintronics, photodiodes, and thermoelectrics. Of particular promise for the development of semiconductor lasers is the possibility to grow GaAsBi laser structures such that the spin–orbit splitting energy ( $\Delta _{{\text{SO}}}$ ) is greater than the bandgap ( $E_{g}$ ) in the active region for devices operating around the telecom wavelength of 1.55 μ m, thereby suppressing the dominant efficiency-limiting loss processes in such lasers, namely Auger recombination and intervalence band absorption. The $\Delta _{{\text{SO}}}\,> \,E_{g}$ band structure is present in GaAsBi alloys containing > 10% Bi, at which composition the alloy bandgap is close to 1.55 μ m on a GaAs substrate making them an attractive candidate material system for the development of highly efficient, uncooled GaAs-based lasers for telecommunications. Here, we discuss progress toward this goal and present a comprehensive set of data on the properties of GaAsBi lasers including optical gain and absorption characteristics and the dominant carrier recombination processes in such systems. Finally, we briefly review the potential of GaAsBiN and InGaAsBi material systems for near- and midinfrared photonic devices on GaAs and InP platforms, respectively.