Effect of thermal annealing on the optical and structural properties of (311)B and (001) GaAsBi/GaAs single quantum wells grown by MBE

Abstract

The effect of Furnace Annealing (FA) and Rapid Thermal annealing (RTA) on the structural and optical properties of GaAs1-xBix/GaAs single quantum wells (SQW) grown on (001) and (311)B substrates by molecular beam epitaxy (MBE) was investigated. The structural properties were investigated by high-resolution X-ray diffraction (HR-XRD) and Transmission Electron Microscopy (TEM). The Bi concentration profiles were determined by simulating the HR-XRD 2θ-ω scans using dynamical scattering theory to estimate the Bi content, lattice coherence and quality of the interfaces. The Bi composition was found to be similar for both samples grown on (001) and (311)B GaAs substrates. However, the simulations indicate that the Bi composition is not only limited in the GaAsBi QW layer but extends out of the GaAsBi QW towards the GaAs barrier. Photoluminescence (PL) measurements were performed as a function of temperature and laser power for samples with a nominal Bi composition of 3%. PL spectra showed that (001) and (311)B samples have different peak energies at 1.23 eV and 1.26 eV, respectively, at 10 K. After RTA at 300 o C for 2 mins, the PL intensity of (311)B and (001) samples was enhanced by a factor of ~2.5 and 1.75, respectively. However, for the (001) and (311)B FA samples an enhancement of the PL intensity by a factor of only 1.5 times could be

Characterization of low-resistance ohmic contacts to heavily carbon-doped n-type InGaAsBi films treated by rapid thermal annealing*

“…As-annealing treatment eliminates defects and improves the electrical properties of carbon-doped InGaAsBi films and, meanwhile, drives more C onto group-III sites as donors, which increases the electron concentration and mobility. [18] A possible mechanism is that as-annealing treatment eliminates Bi-related defects, [28][29][30] drives more Bi onto group-V sites, and increases the number of activated carbon donors by forming C-Bi bonds around the Bi-related defects. [18] Besides, a self-compensation and the incorporation of the carbon atoms in interstitial sites may also be part of the reasons.…”

Growth of InPBi on InP(311)B Substrate by Molecular Beam Epitaxy

“…Dilute Bi compound semiconductors [ 1,2 ] have attracted much attention owing to their unique characteristics such as bandgap narrowing, [ 2–4 ] a temperature‐independent bandgap, [ 5 ] Auger effect suppression, [ 6 ] and improved crystal quality due to the surfactant effects of Bi. [ 7 ] The most commonly investigated dilute bismide system is GaAsBi, [ 8–18 ] and several research groups have demonstrated GaAsBi laser diodes. [ 19,20 ] Although there has been less research on dilute bismides in the InP system, [ 21–23 ] this system is important for longer‐wavelength applications such as fiber optic communications and infrared optics sensing.…”