Influence of AlGaN/GaN/InGaN superlattice on the characteristics of LEDs grown by metalorganic chemical vapor deposition

• Published in: Journal of crystal growth 2010-10, Vol.312 (20), p.2847-2851
• Main Authors: Song, Keun-Man, Kang, Pil-Geun, Shin, Heung-Soo, Kim, Jong-Min, Park, Won-Kyu, Ko, Chul-Gi, Shim, Hyun-Wook, Ho Yoon, Dae
• Format: Article
• Language: English
• Subjects: A1. X-ray diffraction; A3. Metalorganic chemical vapor deposition; Aluminum gallium nitrides; B1. Nitrides; B3. Light-emitting diodes; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Compressive properties; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Density; Electric potential; Exact sciences and technology; Gallium nitrides; Indium gallium nitrides; Insertion; Instruments for strain, force and torque; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Materials science; Mechanical instruments, equipment and techniques; Methods of crystal growth; physics of crystal growth; 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; Photoluminescence; Physics; Stress measurement; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2010.06.028

This study examined the influence of strain-compensated triple AlGaN/GaN/InGaN superlattice structures (SLs) in n-GaN on the structural, electrical and optical characteristics of LEDs by analyzing the etch pits density (EPD), stress measurement, high-resolution X-ray diffraction (HRXRD), sheet resistance, photoluminescence (PL) and light–current–voltage ( L– I– V). EPD, stress measurement and HRXRD studies showed that the insertion of AlGaN/GaN/InGaN SLs during the growth of n-GaN effectively distributed and compensated for the strong compressive stress, and decreased the dislocation density in n-GaN. The operating voltage at 20 mA for the LEDs grown with SLs decreased to 3.18 V from 3.4 V for the LEDs grown without SLs. In addition, a decrease in the spectral blue shift compared to the LEDs grown without SLs was observed in the LEDs grown with the SLs.