MOCVD growth and characterization of near‐surface InGaN/GaN single quantum wells for non‐radiative coupling of optical excitations

Abstract

We report a study of the structural and optical properties of near‐surface InGaN/GaN single quantum wells, grown by metalorganic chemical vapour deposition, as a function of underneath layer structure and GaN capping thickness. Special attention is paid to characterize properties which are important for non‐radiative coupling applications, such as emission intensity at peak wavelength and surface morphology. We observe that utilization of indium containing underneath structures results in high optical quality while increasing surface roughness. Optical performance can be further improved with InGaN/GaN superlattice structures instead of a single InGaN underneath layer. Time‐resolved photoluminescence measurements of samples with different GaN capping thicknesses show that room temperature photoluminescence decay time increases with decreasing GaN capping thickness until surface states related non‐radiative recombination processes start to play a significant role at very small capping thicknesses (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The Mechanisms of AlGaN Device Buffer Layer Growth and Crystalline Quality Improvement: Restraint of Gallium Residues, Mismatch Stress Relief, and Control of Aluminum Atom Migration Length

“…Another important quality index of AlGaN buffer is the surface roughness [28,29]. A smooth surface will actively contribute to the growth of the subsequent layer structure.…”

Förster resonant energy transfer from an inorganic quantum well to a molecular material: Unexplored aspects, losses, and implications to applications

“…The study appears a necessity as apart from few recent reports, [38][39][40]42 the competition of radiative versus surface recombination in such near-surface nitride SQWs remains underexplored. The study involved the systematical investigation of the influence of the following key QW growth parameters: (1) SQW width, (2) SQW InN mole fraction, (3) SQW growth temperature, (4) top cap thickness, (5) top cap content, (6) top cap growth temperature, and (7) top cap n-doping.…”

“…Despite the high dislocation densities, (Ga,In)N quantum wells exhibit high emission yield at room temperature. Importantly, due to the relatively weak nitride surface recombination, 37 nitride QWs appear to retain much of their luminescent efficiency when placed at close proximity to the surface, [38][39][40] a prerequisite for strong donor-acceptor FRET coupling. 1,2 The availability of excellent polymer absorbers from the polyfluorene family in the emission region of such QWs ensures good overlap of donor (QW) emission and acceptor (polymer) absorption, as required for efficient dipoledipole coupling.…”

Exciton dynamics in near-surface InGaN quantum wells coupled to colloidal nanocrystals

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