Study on external quantum efficiency of AlGaInP LEDs

• Main Authors: Liang-Yu Yao, 姚良雨
• Other Authors: Ping Hun
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/23779035181382773322

碩士 === 國立中興大學 === 精密工程研究所 === 93 === In the study, the surface of AlGaInP light emitting diodes were roughened by dry and wet etching methods. Textured surface can increase the emitting area and allow more lights to escape from the surface of LEDs. It will enhance the light intensity and output power. In the dry etching process, polystyrene spheres were used to as natural mask. Polystyrene spheres were coated on the surface of AlGaInP LEDs in a randomly close-packed array. The surface of LEDs was roughened by ICP employing the mixture of Cl2 and Ar gases. After roughing, the light intensity and the outpower of LEDs are increased by 25% and 12% respectively at an operation current of 20mA for light-emitting diode chip of 12 mil size. In the wet etching process, the surface was roughened by the mixture of HF, HNO3, CH3COOH and ICH2COOH solution. The light intensity of LEDs is increased by 15% at an operation current of 20mA for light-emitting diode chip of 12 mil size.