Structural, electronic, and optical properties of $m$-plane InGaN/GaN quantum wells: Insights from experiment and atomistic theory

Abstract

In this paper we present a detailed analysis of the structural, electronic, and optical properties of an $m$-plane (In,Ga)N/GaN quantum well structure grown by metal organic vapor phase epitaxy. The sample has been structurally characterized by x-ray diffraction, scanning transmission electron microscopy, and 3D atom probe tomography. The optical properties of the sample have been studied by photoluminescence (PL), time-resolved PL spectroscopy, and polarized PL excitation spectroscopy. The PL spectrum consisted of a very broad PL line with a high degree of optical linear polarization. To understand the optical properties we have performed atomistic tight-binding calculations, and based on our initial atom probe tomography data, the model includes the effects of strain and built-in field variations arising from random alloy fluctuations. Furthermore, we included Coulomb effects in the calculations. Our microscopic theoretical description reveals strong hole wave function localization effects due to random alloy fluctuations, resulting in strong variations in ground state energies and consequently the corresponding transition energies. This is consistent with the experimentally observed broad PL peak. Furthermore, when including Coulomb contributions in the calculations we find strong exciton localization effects which explain the form of the PL decay transients. Additionally, the theoretical results confirm the experimentally observed high degree of optical linear polarization. Overall, the theoretical data are in very good agreement with the experimental findings, highlighting the strong impact of the microscopic alloy structure on the optoelectronic properties of these systems.

13 pages, 12 figures

References in corpus (4)

• Theory of local electric polarization and its relation to internal strain: impact on the polarization potential and electronic properties of group-III nitrides
• Atomistic analysis of the impact of alloy and well-width fluctuations on the electronic and optical properties of InGaN/GaN quantum wells
• Carrier recombination dynamics in InGaN/GaN multiple quantum wells
• Semiempirical pseudopotential approach for nitride-based nanostructures and {\it ab initio} based passivation of free surfaces

Cited by in corpus (7)

• Polar InGaN/GaN quantum wells: Revisiting the impact of carrier localization on the green gap problem
• Interface roughness, carrier localization and wave function overlap in $c$-plane InGaN/GaN quantum wells: Interplay of well width, alloy microstructure, structural inhomogeneities and Coulomb effects
• Ultrafast, polarized, single-photon emission from m-plane InGaN Quantum Dots on GaN nanowires
• Ga-polar (In,Ga)N/GaN quantum wells vs. N-polar (In,Ga)N quantum disks in GaN nanowires: Comparative analysis of carrier recombination, diffusion, and radiative efficiency
• Theoretical analysis of influence of random alloy fluctuations on the opto-electronic properties of site-controlled (111)-oriented InGaAs/GaAs quantum dots
• A study of the optical and polarisation properties of InGaN/GaN multiple quantum wells grown on a-plane and m-plane GaN substrates
• Experimental and theoretical analyses of strongly polarized photon emission from non-polar InGaN quantum dots