Porous pseudo-substrates for InGaN quantum well growth: Morphology, structure, and strain relaxation
Loading...
Date
2023-10-10
Authors
Ji, Yihong
Frentrup, Martin
Zhang, Xiaotian
Pongrácz, Jakub
Fairclough, Simon M.
Liu, Yingjun
Zhu, Tongtong
Oliver, Rachel A.
ORCID
Advisor
Referee
Mark
Journal Title
Journal ISSN
Volume Title
Publisher
AIP Publishing
Altmetrics
Abstract
Strain-related piezoelectric polarization is detrimental to the radiative recombination efficiency for InGaN-based long wavelength micro-LEDs. In this paper, partial strain relaxation of InGaN multiple quantum wells (MQWs) on the wafer scale has been demonstrated by adopting a partially relaxed InGaN superlattice (SL) as the pseudo-substrate. Such a pseudo-substrate was obtained through an electro-chemical etching method, in which a sub-surface InGaN/InGaN superlattice was etched via threading dislocations acting as etching channels. The degree of strain relaxation in MQWs was studied by x-ray reciprocal space mapping, which shows an increase of the in-plane lattice constant with the increase of etching voltage used in fabricating the pseudo-substrate. The reduced strain in the InGaN SL pseudo-substrate was demonstrated to be transferable to InGaN MQWs grown on top of it, and the engineering of the degree of strain relaxation via porosification was achieved. The highest relaxation degree of 44.7% was achieved in the sample with the porous InGaN SL template etched under the highest etching voltage. Morphological and structural properties of partially relaxed InGaN MQWs samples were investigated with the combination of atomic force and transmission electron microscopy. The increased porosity of the InGaN SL template and the newly formed small V-pits during QW growth are suggested as possible origins for the increased strain relaxation of InGaN MQWs.(c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
Description
Citation
Journal of Aplied Physics. 2023, vol. 134, issue 14, p. 1-10.
https://pubs.aip.org/aip/jap/article/134/14/145102/2916034/Porous-pseudo-substrates-for-InGaN-quantum-well
https://pubs.aip.org/aip/jap/article/134/14/145102/2916034/Porous-pseudo-substrates-for-InGaN-quantum-well
Document type
Peer-reviewed
Document version
Published version
Date of access to the full text
Language of document
en