Title :
Enhanced Performance of a GaN-Based LED Prepared by an Anodized Aluminum Oxide-Nanoporous Pattern Sapphire Substrate
Author :
Zong-Jie Tsai ; Jian-Kai Liou ; Wen-Chau Liu
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Abstract :
A new approach to fabricate a GaN light-emitting diode (LED), grown on an anodized aluminum oxide-nanoporous pattern sapphire substrate (AAO-NPSS), is studied. An AAO film is used as a dry etching mask to transfer nanoporous patterns on the sapphire substrate. Because of the use of AAO-NPSS, threading dislocations could be reduced and air voids would be formed to reflect downward photons toward top direction. As compared with a conventional LED, at 20 mA, the AAO-NPSS-based device exhibits 52.8% enhancements of light output power. The reduced leakage current and lower turn-on voltage are also achieved. Therefore, the use of AAO-NPSS structure could effectively improve the crystalline quality and light extraction efficiency, which certainly leads to the enhanced performance of GaN LEDs.
Keywords :
III-V semiconductors; aluminium compounds; etching; gallium compounds; leakage currents; light emitting diodes; sapphire; wide band gap semiconductors; AAO film; AAO-NPSS-based device; GaN; GaN-based LED; anodized aluminum oxide; crystalline quality; current 20 mA; dry etching mask; leakage current; light extraction efficiency; light-emitting diode; nanoporous pattern; photons; sapphire substrate; turn-on voltage; Air voids; GaN; anodized aluminum oxide (AAO); light-emitting diodes (LEDs); nanoporous pattern sapphire substrate (NPSS); threading dislocations (TDs);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2013.2264353