Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED Sidewall

Abstract Elastic relaxation of lattice misfit strain via traction‐free surface results in complex 3D strain distribution and morphological modification at the boundary of epitaxial heterostructure. While this phenomenon is extensively studied, the influence of the interface coherency constraining th...

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Main Authors: Jongil Kim, Jinwook Yeo, Bumsu Park, Jeehun Jeong, Seunghwa Ryu, Sang Ho Oh
Format: Article
Language:English
Published: Wiley 2025-05-01
Series:Advanced Science
Subjects:
Online Access:https://doi.org/10.1002/advs.202408736
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author Jongil Kim
Jinwook Yeo
Bumsu Park
Jeehun Jeong
Seunghwa Ryu
Sang Ho Oh
author_facet Jongil Kim
Jinwook Yeo
Bumsu Park
Jeehun Jeong
Seunghwa Ryu
Sang Ho Oh
author_sort Jongil Kim
collection DOAJ
description Abstract Elastic relaxation of lattice misfit strain via traction‐free surface results in complex 3D strain distribution and morphological modification at the boundary of epitaxial heterostructure. While this phenomenon is extensively studied, the influence of the interface coherency constraining the strain relaxation has received little attention. Here it is shown that the interfacial shear stresses arise toward the traction free sidewall of microscale light emitting diode (LED) wires while the two complementary strained InGaN and GaN layers are relaxed to revert their bulk lattice parameters near the sidewall. The shear stresses with opposite signs achieve mechanical equilibrium by counterbalancing the change in the sign of the in‐plane strain in each layer of the near‐surface region. A unique nonmonotonic modulation of both normal and shear strain is detected unambiguously in the strain maps and corroborated by finite element modeling. An analytical model is developed based on the Airy stress function, which incorporates the superposition of alternating in‐plane pre‐stress and the image stress to satisfy the boundary condition. The resultant complex strain fields in microscale LEDs, where surface emission is dominant, alter strain‐induced piezoelectric polarization near the surface, significantly affecting electro‐optical efficiency and resulting in spectral broadening and/or wavelength shifts in emitted light.
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institution Kabale University
issn 2198-3844
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spelling doaj-art-16ba53ac69f240b58d330a2acdc1c8b42025-08-20T03:47:33ZengWileyAdvanced Science2198-38442025-05-011219n/an/a10.1002/advs.202408736Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED SidewallJongil Kim0Jinwook Yeo1Bumsu Park2Jeehun Jeong3Seunghwa Ryu4Sang Ho Oh5Department of Energy Engineering Institute of Energy Materials and Devices Korea Institute of Energy Technology (KENTECH) Naju 58330 Republic of KoreaDepartment of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of KoreaCEMES‐CNRS 29 rue. J. Marvig Toulouse 31055 FranceDepartment of Energy Engineering Institute of Energy Materials and Devices Korea Institute of Energy Technology (KENTECH) Naju 58330 Republic of KoreaDepartment of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of KoreaDepartment of Energy Engineering Institute of Energy Materials and Devices Korea Institute of Energy Technology (KENTECH) Naju 58330 Republic of KoreaAbstract Elastic relaxation of lattice misfit strain via traction‐free surface results in complex 3D strain distribution and morphological modification at the boundary of epitaxial heterostructure. While this phenomenon is extensively studied, the influence of the interface coherency constraining the strain relaxation has received little attention. Here it is shown that the interfacial shear stresses arise toward the traction free sidewall of microscale light emitting diode (LED) wires while the two complementary strained InGaN and GaN layers are relaxed to revert their bulk lattice parameters near the sidewall. The shear stresses with opposite signs achieve mechanical equilibrium by counterbalancing the change in the sign of the in‐plane strain in each layer of the near‐surface region. A unique nonmonotonic modulation of both normal and shear strain is detected unambiguously in the strain maps and corroborated by finite element modeling. An analytical model is developed based on the Airy stress function, which incorporates the superposition of alternating in‐plane pre‐stress and the image stress to satisfy the boundary condition. The resultant complex strain fields in microscale LEDs, where surface emission is dominant, alter strain‐induced piezoelectric polarization near the surface, significantly affecting electro‐optical efficiency and resulting in spectral broadening and/or wavelength shifts in emitted light.https://doi.org/10.1002/advs.202408736GaNinterfacelight emitting diodesmicrowirestraintransmission electron microscopy
spellingShingle Jongil Kim
Jinwook Yeo
Bumsu Park
Jeehun Jeong
Seunghwa Ryu
Sang Ho Oh
Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED Sidewall
Advanced Science
GaN
interface
light emitting diodes
microwire
strain
transmission electron microscopy
title Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED Sidewall
title_full Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED Sidewall
title_fullStr Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED Sidewall
title_full_unstemmed Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED Sidewall
title_short Elastic Relaxation of Coherent InGaN/GaN Interfaces at the Microwire LED Sidewall
title_sort elastic relaxation of coherent ingan gan interfaces at the microwire led sidewall
topic GaN
interface
light emitting diodes
microwire
strain
transmission electron microscopy
url https://doi.org/10.1002/advs.202408736
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AT jinwookyeo elasticrelaxationofcoherentinganganinterfacesatthemicrowireledsidewall
AT bumsupark elasticrelaxationofcoherentinganganinterfacesatthemicrowireledsidewall
AT jeehunjeong elasticrelaxationofcoherentinganganinterfacesatthemicrowireledsidewall
AT seunghwaryu elasticrelaxationofcoherentinganganinterfacesatthemicrowireledsidewall
AT sanghooh elasticrelaxationofcoherentinganganinterfacesatthemicrowireledsidewall