Impact of in-situ annealing on dilute-bismide materials and its application to photovoltaics

Impact of Rotation Rate on Bismuth Saturation in GaAsBi Grown by Molecular Beam Epitaxy

“…To explore further the effects of temperature on bismuth compositional variations, as-grown GaAsBi samples with rotation-induced VCMs were annealed ex situ in a rapid thermal processor. As bismide materials must be grown below temperatures ideal for most III-V materials, extensive work in literature has documented the effects of annealing GaAsBi both ex situ in rapid thermal processors [29][30][31] and in situ after growth 32,33 to simulate the effects of subsequent device layer growth. Previous research has found that bulk GaAsBi is fairly stable up to temperatures of 700°C to 800°C, above which bismuth diffusion begins to occur.…”

Large-scale atomistic simulations demonstrate dominant alloy disorder effects in GaBixAs1−x/GaAs multiple quantum wells

“…Bismide alloys formed by dilute impurity concentrations of Bi atoms in GaAs are a rapidly emerging material system for the design of photonic devices [1][2][3][4][5], photovoltaics [6][7][8], spintronic devices [9], and thermoelectric applications [10]. The experimental and theoretical investigations of both unstrained and strained bulk GaBi x As 1−x alloys have shown promising properties with increasing Bi fractions such as a large band gap reduction [5,[11][12][13], a crossover between the band gap and spin split-off energies [12][13][14], and the possibility of lattice-matched growth on a GaAs substrate [15].…”

Annealing-induced precipitate formation behavior in MOVPE-grown GaAs1−xBixexplored by atom probe tomography and HAADF-STEM

“…Through understanding and manipulating the physical and chemical processes that occur during both molecular beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE) [3][4][5][6][7] it is now possible to fabricate single-phase epitaxial films with thicknesses ranging from a few to a few hundred nanometers and homogeneous Bi concentrations up to as high as x≈0.07 [5] and x≈0.22 [8] for MOVPE and MBE-deposited materials, respectively. As a result, GaAs 1−x Bi x materials have been implemented in operative solar cell [9] and quantum-well laser diode [10][11][12] devices, demonstrating their potential to enable new device capabilities and driving development of new device structures. Such successes also drive investigations of the stability of these metastable materials that target understanding, predicting, and controlling the evolution of microstructure, electronic structure, and physical properties during subsequent materials processing, device processing, and device use.…”