Title :
Enhanced Performance of LEDs Using Periodic Tent-Like Post Patterns on A-plane Sapphire Substrates
Author :
Lin, Bo-Wen ; Chang, Chung-Cheng ; Hsieh, Cheng-Yu ; Wang, Bau-Ming ; Wu, YewChung Sermon ; Hsu, Wen-Ching
Author_Institution :
Dept. of Mater. Sci. & Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
Periodic tent-like post patterns on a-plane sapphire substrates were fabricated using a two-step etching process. They were denoted as a-plane dot pattern sapphire substrate (ADPSS). Compared with the GaN-based light-emitting diode (LED) grown on a-plane sapphire without any pattern (AFlat), the ADPSS-LED has higher output power, light extraction efficiency (LEE), and external quantum efficiency (EQE), and better crystal quality. The output power of ADPSS-LED was 9.6 mW, which was 68.4% larger than the AFlat-LED. In addition, the blue shift of ADPSS-LED was found to be less than that of AFlat-LED.
Keywords :
etching; light emitting diodes; sapphire; spectral line shift; A-plane sapphire substrates; Al2O3; LED; a-plane dot pattern sapphire substrate; blue shift; crystal quality; external quantum efficiency; light extraction efficiency; periodic tent-like post patterns; power 9.6 mW; two-step etching process; Arrays; Crystals; Epitaxial growth; Gallium nitride; Light emitting diodes; Power generation; Substrates; A-plane; light-emitting diode (LED); sapphire;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2011.2167677
