Title :
Advances of AlGaN-based high-efficiency deep-UV LEDs
Author :
Hirayama, Hideki
Author_Institution :
RIKEN, Wako, Japan
Abstract :
We demonstrated AlGaN-based multi-quantum-well (MQW) deep-ultraviolet (UV) light-emitting diodes (LEDs) with wavelengths in the range of 222-351 nm, fabricated on low threading dislocation density (TDD) AlN template on sapphire. A high internal quantum efficiency (IQE) of 50-80% was achieved from AlGaN or quaternary InAlGaN MQWs by fabricating them on low TDD AlN templates. Also, an electron injection efficiency (EIE) was markedly improved by using multi-quantum barrier (MQB). Over 20 mW cw output power was obtained for 256-275 nm LEDs, which will be useful for sterilization applications. The maximum external quantum efficiencies (EQEs) were 1.8 and 2.75% for 247 and 270 nm AlGaN-LEDs, respectively.
Keywords :
III-V semiconductors; aluminium compounds; light emitting diodes; quantum wells; substrates; efficiency 50 percent to 80 percent; electron injection efficiency; external quantum efficiencies; high-efficiency deep-UV LED; internal quantum efficiency; multi-quantum barrier; multi-quantum-well deep-ultraviolet light-emitting diodes; threading dislocation density; wavelength 222 nm to 351 nm; Aluminum gallium nitride; Electrodes; Light emitting diodes; Nickel; Power generation; Quantum well devices; Temperature measurement;
Conference_Titel :
Communications and Photonics Conference and Exhibition (ACP), 2010 Asia
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-7111-9
DOI :
10.1109/ACP.2010.5682667
