TY - JOUR

T1 - Defect Structure and Luminescence of κ-Ga2O3 Micro-Monocrystals

AU - Vyvenko, O.F.

AU - Shapenkov, S.V.

AU - Ubyivovk, E.V.

AU - Bondarenko, A.S.

AU - Varygin, G.V.

AU - Pechnikov, A.I.

AU - Nikolaev, V.I.

N1 - Export Date: 4 November 2024 Сведения о финансировании: Russian Science Foundation, RSF, 23–23–00202 Сведения о финансировании: Russian Science Foundation, RSF Текст о финансировании 1: This study was funded by the Russian Science Foundation grant no. 23\u201323\u201300202, https://rscf.ru/project/23\u201323\u201300202 . The experimental part was performed using equipment of the Interdisciplinary Resource Center for Nanotechnology and of the Research Center for X\u2010ray Diffraction Study of Saint\u2010Petersburg University. The authors are grateful to V. Yu Mikhailovsky for the FIB lamella preparation and to Perfect Crystals LLC for providing the GaO layers. 2 3

PY - 2024/10/24

Y1 - 2024/10/24

N2 - Wide bandgap orthorhombic polymorph of gallium oxide (κ-Ga2O3) possessing a high spontaneous polarization grown on wurtzite-type semiconducting substrates is considered to create a high mobility electron channel suitable for applications. Such κ-Ga2O3 layers are composed of hexagon microprisms whose properties affect the lateral electric conductance. In this work, the structure and recombination properties of extended defects in individual “suspended” thin microprisms are investigated with transmission and scanning electron microscopy techniques (STEM, HR-TEM) including cathodoluminescence (CL-SEM). It is established that the microprism is composed of six equisized orthorhombic domains bounded by twin domain boundaries (TDBs) along the directions <110>. Twin domain contains a parallel array of antiphase boundaries (APB) of a high density stretched in the [010] direction. APBs possess steps or interruption and can form double oppositely shifted spatially separated layers (APB dipoles). TDBs on majority of their length are incoherent and serve as the border for the APB terminations. Panchromatic CL maps reveal either enhanced or reduced intensity of APB without noticeable spectral changes. CL intensity enhancement is proposed to be due to enhanced electron–hole generation caused by excess scattering of primary electron beam by APBs in thin films while, in fact, APB exhibits enhanced nonradiative recombination activity. © 2024 Wiley-VCH GmbH.

AB - Wide bandgap orthorhombic polymorph of gallium oxide (κ-Ga2O3) possessing a high spontaneous polarization grown on wurtzite-type semiconducting substrates is considered to create a high mobility electron channel suitable for applications. Such κ-Ga2O3 layers are composed of hexagon microprisms whose properties affect the lateral electric conductance. In this work, the structure and recombination properties of extended defects in individual “suspended” thin microprisms are investigated with transmission and scanning electron microscopy techniques (STEM, HR-TEM) including cathodoluminescence (CL-SEM). It is established that the microprism is composed of six equisized orthorhombic domains bounded by twin domain boundaries (TDBs) along the directions <110>. Twin domain contains a parallel array of antiphase boundaries (APB) of a high density stretched in the [010] direction. APBs possess steps or interruption and can form double oppositely shifted spatially separated layers (APB dipoles). TDBs on majority of their length are incoherent and serve as the border for the APB terminations. Panchromatic CL maps reveal either enhanced or reduced intensity of APB without noticeable spectral changes. CL intensity enhancement is proposed to be due to enhanced electron–hole generation caused by excess scattering of primary electron beam by APBs in thin films while, in fact, APB exhibits enhanced nonradiative recombination activity. © 2024 Wiley-VCH GmbH.

KW - antiphase boundaries

KW - cathodoluminescence

KW - gallium oxide

KW - transmission electron microscopy

KW - twin domain boundaries

UR - https://www.mendeley.com/catalogue/0a3fc64e-59f8-37f7-ae4d-ecec74e2e8b5/

U2 - 10.1002/pssb.202400435

DO - 10.1002/pssb.202400435

M3 - статья

JO - Physica Status Solidi (B): Basic Research

JF - Physica Status Solidi (B): Basic Research

SN - 0370-1972

ER -