Improved optical properties of InGaN/GaN light-emitting diodes with In preflow quantum wells

• Main Authors: Yu-Jin Liu, 劉昱進
• Other Authors: Chong-Yi Lee
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/73660366853405327470

碩士 === 義守大學 === 電子工程學系碩士班 === 98 === Blue multi-quantum-well light emitting diodes (LEDs) with In preflow quantum-wells (QWs) were grown by using metal-organic chemical vapor deposition (MOCVD). The smaller blue shift of the EL spectra was not significant as the input current was increased, indicating that the carrier localization effect resulting from the quantum-confined Stark effect (QCSE) in the sample with five-second In preflow was suppressed. The five-second In preflow LEDs show decreased wavelength shift, increased light output power and reduced efficiency droop compared with MQWs grown without In preflow LEDs. In addition, the MQW structure with ten-second In preflow exhibited inferior quality and lower photoluminescence (PL) intensity. These negative results could result from the redundant In preflow time which increased defect density and lower internal quantum efficiency.