@article{oai:nitech.repo.nii.ac.jp:00004817, author = {Ishikawa, Hiroyasu and Nakada, Naoyuki and Nakaji, Masaharu and Zhao, Guang-Yuan and Egawa, Takashi and Jimbo, Takashi and Umeno, Masayoshi}, issue = {4}, journal = {IEICE transactions on electronics}, month = {Apr}, note = {Investigations were carried out on metalorganic-chemical-vapor-deposition (MOCVD)-grown strained AlGaN/ GaN/sapphire structures using X-ray diffratometry. While AlGaN with lower AlN molar fraction (< 0.1) is under the in-plane compressive stress, it is under the in-plane tensile stress with high AlN molar fraction (> 0.1). Though tensile stress caused the cracks in AlGaN layer with high AlN molar fraction, we found that the cracks dramatically reduced when the GaN layer quality was not good. Using this technique, we fabricated a GaInN multi-quantum-well (MQW) surface emitting diodes were fabricated on 15 pairs of AlGaN/GaN distributed Bragg reflector (DBR) structures. The reflectivity of 15 pairs of AlGaN/GaN DBR structure has been shown as 75% at 435 nm. Considerably higher output power (1.5 times) has been observed for DBR based GaInN MQW LED when compared with non-DBR based MQW structures., application/pdf}, pages = {591--597}, title = {Investigations on Strained AlGaN/GaN/Sapphire and GaInN Multi-Quantum-Well Surface LEDs Using AlGaN/GaN Bragg Reflectors}, volume = {E83-C}, year = {2000} }