Quaternary bismide alloy ByGa1−yAs1−xBixByGa1−yAs1−xBix lattice matched to GaAs

We report on the lattice matched quaternary alloy, ByGa1−yAs1−xBixByGa1−yAs1−xBix grown by molecular beam epitaxy at conditions conducive to bismuth incorporation. Incorporating a smaller atom (boron) along with the larger atom (bismuth) allows for a reduction of the epi-layer strain and lattice matching to GaAs for compositions of Bi:B≃1.3:1Bi:B≃1.3:1. The addition of boron flux does not significantly affect the bismuth incorporation and no change in the band gap energy is observed with increasing boron content. However, excess, non-substitutional boron is incorporated which leads to an increase in hole density, as well as an increase in the density of shallow in-gap states as observed by the loss of localization of photo-excited excitons.

► Boron in incorporated in GaAs at GaAsBi-like conditions.► ByGa1−yAs1−xBixByGa1−yAs1−xBix is lattice matched for GaAs for [Bi]:[B]s≃1.3:1[Bi]:[B]s≃1.3:1. ► The incorporation of boron does not significantly effect the band gap of GaAs1−xBixGaAs1−xBix. ► Excess incorporated boron lead to an increase in the density of shallow impurities and acceptors.