In this study, five periodic InGaN
/ GaN LED (light emitting diode) structures grown by the Metal Organic Vapor
Deposition (MOCVD) at different active layer growth temperatures were studied.
These structures were grown as InGaN / GaN multiple quantum wells (MQW) between
c-oriented sapphire substrate and n-GaN and p-AlGaN + GaN contacts. These
constructions were characterized by the high-resolution X-ray diffraction
(HR-XRD) system. HRXRD patterns obtained by X-ray diffraction and Reciprocal
space maps were performed from the same data. One of the most effective ways of
studying the crystal lattice is reciprocal space mapping with HR-XRD technique.
This technique does not damage the sample. Information can be obtained from the
internal system of the sample or from the intermediate layer including
substrate. Using the FWHM (βhkl) values and the elastic coefficients
of the structures obtained for each of the three samples separately with the
inverse mesh technique, D (nm) particle size, σ (GPa) uniform stress, ε strain,
u (kJm-3) anisotropic energy density parameters were calculated.
These calculations were done in a
Scherrer method and Uniform Deformation Model (UDM) which is the
Williamson Hall method, modified uniform Williamson stresses model (USDM) and
Uniform Deformation Energy Density Model (UDEDM). The results show that the
stretching in the crystal size is very little. Line expansion in HR-XRD is due
to small crystal size and lattice strain. UDEDM, one of the W-H methods, has
emerged as the most suitable model for stretching..
In this study, five periodic InGaN
/ GaN LED (light emitting diode) structures grown by the Metal Organic Vapor
Deposition (MOCVD) at different active layer growth temperatures were studied.
These structures were grown as InGaN / GaN multiple quantum wells (MQW) between
c-oriented sapphire substrate and n-GaN and p-AlGaN + GaN contacts. These
constructions were characterized by the high-resolution X-ray diffraction
(HR-XRD) system. HRXRD patterns obtained by X-ray diffraction and Reciprocal
space maps were performed from the same data. One of the most effective ways of
studying the crystal lattice is reciprocal space mapping with HR-XRD technique.
This technique does not damage the sample. Information can be obtained from the
internal system of the sample or from the intermediate layer including
substrate. Using the FWHM (βhkl) values and the elastic coefficients
of the structures obtained for each of the three samples separately with the
inverse mesh technique, D (nm) particle size, σ (GPa) uniform stress, ε strain,
u (kJm-3) anisotropic energy density parameters were calculated.
These calculations were done in a
Scherrer method and Uniform Deformation Model (UDM) which is the
Williamson Hall method, modified uniform Williamson stresses model (USDM) and
Uniform Deformation Energy Density Model (UDEDM). The results show that the
stretching in the crystal size is very little. Line expansion in HR-XRD is due
to small crystal size and lattice strain. UDEDM, one of the W-H methods, has
emerged as the most suitable model for stretching..
Primary Language | English |
---|---|
Subjects | Engineering |
Journal Section | Research Article |
Authors | |
Publication Date | March 1, 2019 |
Submission Date | October 24, 2017 |
Published in Issue | Year 2019 Volume: 22 Issue: 1 |
This work is licensed under Creative Commons Attribution-ShareAlike 4.0 International.