Title :
Improved Output Power of Nitride-Based Light-Emitting Diodes With Convex-Patterned Sapphire Substrates
Author :
Hsu, Yu-Ting ; Yu, Cheng-Chang ; Huang, Kai-Feng ; Lan, Wen-How ; Huang, Jing-En ; Lin, Jia-Ching ; Lin, Wen-Jen
Author_Institution :
Dept. of Electrophys., Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
Nitride-based light-emitting diodes (LEDs) grown on different convex-patterned sapphire substrates are proposed and fabricated. The electrical and optical properties of these LEDs are discussed in detail. It is found that the LED with a ball-shape patterned sapphire substrate has the best crystalline quality and I-V characteristic. On the other hand, on reducing total internal reflection, the LED with hexagonal-shape patterned sapphire substrate (HPSS) has the best performance on output power and external quantum efficiency. In comparison to the LED without patterned substrate, the LED with HPSS has 175% and 165% enhancement on output power and external quantum efficiency, respectively.
Keywords :
III-V semiconductors; gallium compounds; indium compounds; light emitting diodes; light reflection; optical fabrication; wide band gap semiconductors; Al2O3; HPSS; I-V characteristics; InGaN-GaN; LED output power; ball-shape patterned sapphire substrate; convex-patterned sapphire substrates; crystalline quality; electrical properties; external quantum efficiency; hexagonal-shape patterned sapphire substrate; nitride-based light-emitting diodes; optical properties; total internal reflection; Cascading style sheets; Gallium nitride; Light emitting diodes; Photonics; Power generation; Substrates; Surface treatment; External quantum efficiency (EQE); light-emitting diodes (LEDs); patterned sapphire substrate (PSS);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2012.2212425
