Strain variation in p-GaN by different spacer layers in the light emitting diodes and their microstructural and emission behaviors

• Published in: Journal of crystal growth 2010-07, Vol.312 (14), p.2128-2132
• Main Authors: Kong, Bo Hyun, Cho, Hyung Koun, Yang Kim, Mi, Jun Choi, Rak, Kyun Kim, Bae
• Format: Article
• Language: English
• Subjects: A3. Metalorganic chemical vapor deposition; Applied sciences; B1. Nitrides; B2. Semiconducting III–V materials; B3. Light emitting diodes; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal growth; Deterioration; Devices; Electroluminescence; Electronics; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Gallium nitrides; Indium gallium nitrides; Light-emitting diodes; Magnesium; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optoelectronic devices; Other luminescence and radiative recombination; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solubility, segregation, and mixing; phase separation; Spacers; Strain
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2010.03.037

InGaN/GaN multiple quantum well-based blue light emitting diodes (LEDs) with different spacer layer structures were grown by metalorganic chemical vapor deposition. Fast-Fourier-transformed high-resolution transmission electron microscopy was used to determine the influence of the strain status in the spacer layer on Mg distribution and device performance. A comparison of the (1 1¯ 0 0) planar distance showed that the high-temperature grown InGaN layer in the spacer had a high level of stored strain. This led to the formation of a continuous facet contrast induced by Mg segregation in the p-layer, which was responsible for the deterioration of the electroluminescence performance of the LEDs. These results show that the delicate control of stored strain in nitride films is important for improving the device performance.