IMPROVEMENT OF CRYSTAL QUALITY AND OPTICAL PROPERTY IN (11-22) SEMIPOLAR InGaN/GaN LIGHT EMITTING DIODES GROWN ON HEMI-SPHERICALLY PATTERNED SiO2 MASK

• Published in: Journal of Ceramic Processing Research Vol. 14; no. 4; pp. 521 - 524
• Main Authors: Min, D, Yoo, G, Ryu, Y, Moon, S, Lee, K, Nam, O
• Format: Journal Article
• Language: English
• Published: 청정에너지연구소 2013
• Subjects: Crystal defects; Crystals; Gallium nitrides; Indium gallium nitrides; Light-emitting diodes; Masks; Optical properties; Sapphire; 재료공학
• ISSN: 1229-9162; 2672-152X
• DOI: 10.36410/jcpr.2013.14.4.521

Improved crystal quality and optical properties are reported in (11-22) semipolar InGaN/GaN light emitting diodes (LEDs) grown on a hemi-spherically patterned SiO2 mask on an m-plane sapphire substrate (HP-SiO2) compared with the m-plane sapphire substrate (m-planar), using metallorganic chemical vapour deposition (MOCVD). The photoluminescence (PL) results showed that the integrated intensity of the near band edge (NBE) emission of the GaN layer grown on HP-SiO2 was increased by 3 times compared with that of m-planar. The full width at half maximums (FWHMs) of X-ray rocking curves for the on- and off-axis planes of the GaN layers on HP-SiO2 were narrower than that on m-planar, indicating that the crystal quality of the semipolar GaN layers on HP-SiO2 was considerably improved as compared with that on m-planar by reducing defects such as perfect/partial dislocations and basal stacking faults. Cross-sectional TEM images also showed the reduction of dislocation density in GaN layers on HP-SiO2 than on m-planar. The optical power of InGaN/GaN LEDs with HP-SiO2 was increased by 1.7 and 7.3 times at an injection current of 20 mA and 100 mA, respectively, in comparison with the m-planar LEDs.