Title :
Lifetime Tests and Junction-Temperature Measurement of InGaN Light-Emitting Diodes Using Patterned Sapphire Substrates
Author :
Tsai, P.C. ; Chuang, Ricky W. ; Su, Y.K.
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan
Abstract :
The authors demonstrate nitride-based blue light-emitting diodes with an InGaN/GaN (460 nm) multiple quantum-well structure on the patterned sapphire substrates (PSSs) compared with conventional sapphire substrates (CSSs) using metal-organic chemical vapor deposition. According to full-width at half-maximum of high-resolution X-ray diffraction and transmission electron microscopy micrographs, the dislocation density of GaN epilayers grown on the PSS was lower than those of the CSS. It was found that the output power of devices on PSS was 26% larger than that of CSS. The lifetime defined by 50% loss in output power was 590 and 305 h at 85 degC for the PSS and CSS, respectively. It was also found that the junction temperature and thermal resistance were smaller for the PSS. These improvements are attributed to the reduction in dislocation density using PSS structure
Keywords :
III-V semiconductors; MOCVD; X-ray diffraction; dislocation density; gallium compounds; indium compounds; integrated optoelectronics; light emitting diodes; quantum well devices; sapphire; semiconductor junctions; thermal resistance; transmission electron microscopy; 305 h; 460 nm; 590 h; 85 degC; Al2O3; GaN epilayers; InGaN light-emitting diodes; InGaN-GaN; X-ray diffraction; blue light-emitting diodes; dislocation density; full-width at half-maximum; junction-temperature measurement; lifetime tests; metal-organic chemical vapor deposition; multiple quantum-well structure; nitride-based light-emitting diodes; patterned sapphire substrates; thermal resistance; transmission electron microscopy micrographs; Cascading style sheets; Chemical vapor deposition; Electrons; Gallium nitride; Lifetime estimation; Light emitting diodes; Power generation; Quantum well devices; Thermal resistance; X-ray diffraction; GaN; junction temperature; light-emitting diode (LED); patterned sapphire substrate; thermal resistance;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2006.888234