MBE growth strategy and optimization of GaAsBi quantum well light emitting structure beyond 1.2 μm

Abstract

GaAs1−xBix/AlGaAs quantum wells (QWs) with varying As/Ga beam equivalent pressure (BEP) ratios were grown by solid source molecular beam epitaxy at a relatively high temperature of 350–400 °C intended for light emitting applications with wavelengths beyond 1.2 μm. Both the Bi content and the photoluminescence (PL) intensity were found to be highly dependent on As2 flux, especially for the case of growing GaAsBi at a relatively high temperature. A graded index separate confinement GaAsBi/AlGaAs single QW with 5.8% Bi exhibited a strong PL emission at 1.22 μm. The growth strategy to incorporate considerable Bi into GaAs at a relatively high temperature through meticulous control of the As/Ga BEP ratio and compensation of Bi flux is demonstrated to be effective in guaranteeing a high Bi content as well as an optimal optical performance of GaAsBi QWs.

GaAsBi: From Molecular Beam Epitaxy Growth to Devices

“…Figure 7 shows a mapping of the reported substrate temperatures and epilayer Bi contents from the literature. [ 1,10,36,37,89–103 ] Most of the growth effort has been concentrated on relatively low (<10%) Bi contents and relatively high (>300 °C) growth temperatures, although some groups have targeted lower growth temperatures and higher Bi contents. The hashed area in Figure 7 is not a theoretical limit, rather it is simply a guide to the eye.…”

GaAsBi: From Molecular Beam Epitaxy Growth to Devices

“…Figure 7 shows a mapping of the reported substrate temperatures and epilayer Bi contents from the literature. [1,10,36,37,[91][92][93][94][95][96][97][98][99][100][101][102][103][104][105] Most of the growth effort has been concentrated on relatively low (< 10 %) Bi contents and relatively high (> 300 °C) growth temperatures, although some groups have targeted lower growth temperatures and higher Bi contents. The hashed area in figure 7 is not a theoretical limit, rather it is simply a guide to the eye.…”

High verticality vapor–liquid–solid growth of GaAs0.99Bi0.01 nanowires using Ga–Bi assisted catalytic droplets

“…7 Despite the advantages, the optimal growth window for GaAsBi is narrow. The growth temperatures and the V/III flux ratios must be well-controlled 8–13 to incorporate Bi atoms without triggering other challenges during the epitaxial growth, such as phase separation, 14 surface droplets, 15,16 and atomic ordering. 17–19…”