Optical properties of metamorphic type-I InAs1−xSbx/Aly In1−y As quantum wells grown on GaAs for the mid-infrared spectral range

Peter J Carrington,Qi Lu,Maria De La Mata,Christopher A Broderick,Andrew R J Marshall,Eoin P O’Reilly,Eva Repiso,Reza Arkani,Sergio I Molina,Anthony Krier

doi:10.1088/1361-6463/ab37cf

Peter J Carrington, Qi Lu + Show 8 more

Open Access

https://doi.org/10.1088/1361-6463/ab37cf

Copy DOI

Abstract

We analyse the optical properties of InAs1−xSbx/Aly In1−y As quantum wells (QWs) grown by molecular beam epitaxy on relaxed Aly In1−y As metamorphic buffer layers (MBLs) using GaAs substrates. The use of Aly In1−y As MBLs allows for the growth of QWs having large type-I band offsets, and emission wavelengths >3 m. Photoluminescence (PL) measurements for QWs having Sb compositions up to x = 10% demonstrate strong room temperature PL up to 3.4 m, as well as enhancement of the PL intensity with increasing wavelength. To quantify the trends in the measured PL we calculate the QW spontaneous emission (SE), using a theoretical model based on an eight-band Hamiltonian. The theoretical calculations, which are in good agreement with experiment, identify that the observed enhancement in PL intensity with increasing wavelength is associated with the impact of compressive strain on the QW valence band structure, which reduces the band edge density of states making more carriers available to undergo radiative recombination at fixed carrier density. Our results highlight the potential of type-I InAs1−xSbx/Aly In1−y As metamorphic QWs to address several limitations associated with existing heterostructures operating in the mid-infrared, establishing these novel heterostructures as a suitable platform for the development of light-emitting diodes and diode lasers.

Highlights

We analyse the optical properties of InAs1−xSbx/AlyIn1−yAs quantum wells (QWs) grown by molecular beam epitaxy on relaxed AlyIn1−yAs metamorphic buffer layers (MBLs) using GaAs substrates
The theoretical calculations, which are in good agreement with experiment, identify that the observed enhancement in PL intensity with increasing wavelength is associated with the impact of compressive strain on the QW valence band structure
Further limitations to achieving λ 3 μm in GaSb-based heterostructures relate to the presence of (i) a miscibility gap in In- and As-rich GaInAsSb alloys, leading to a reduction in material quality, and (ii) a band structure in which the valence band (VB) spin-orbit splitting energy is close in magnitude to the band gap, leading to increased hot-hole producing (CHSH) Auger recombination and inter-valence band absorption

Summary

Introduction

Significant advances have been made in the development of GaSb-based diode lasers and light emitting diodes (LEDs).[5,6,7] In the 2 – 3 μm spectral range type-I GaInAsSb/AlGa(In)AsSb QWs have demonstrated impressive characteristics, but their performance at and above room temperature degrades significantly for wavelengths λ 3 μm due to a combination of Auger recombination and thermal leakage of holes.[8,9,10,11] Further limitations to achieving λ 3 μm in GaSb-based heterostructures relate to the presence of (i) a miscibility gap in In- and As-rich GaInAsSb alloys, leading to a reduction in material quality, and (ii) a band structure in which the valence band (VB) spin-orbit splitting energy is close in magnitude to the band gap, leading to increased hot-hole producing (CHSH) Auger recombination and inter-valence band absorption. Band structure of bulk-like InAs1−xSbx epitaxial layers grown on AlyIn1−yAs MBLs. The solid blue (dashed red) lines in Fig. 2(a) denote compositions for which the band gap Eg (in-plane strain xx) is constant.

Results

Conclusion