Effect of strain relaxation and exciton localization on performance of 350-nm AlInGaN quaternary light-emitting diodes

The optical and structural properties of AlInGaN quaternary single and multiple quantum-well structures have been investigated by means of photoluminescence and x-ray diffraction. This comparative study of single quantum-well (SQW) and multiple quantum-well (MQW) structures was carried out in terms of the exciton localization effect and the strain relaxation. A detailed analysis indicated that 13% strain relaxation occurs in the MQW compared to the SQW, which is assumed to be fully strained. Furthermore, the AlInGaN SQW structure showed a stronger localization effect than the MQW. Both these effects result in enhanced emission efficiency for the SQW structure, indicating that it is better suited as the active region for ultraviolet light-emitting diodes (UV-LEDs). Finally, the UV-LEDs with an emission wavelength of about 350nm based on such SQW and MQW active regions were grown. The output power of the SQW UV-LEDs is around 2.3 times higher than that of MQW UV-LEDs.

[1]  Tao Wang,et al.  High-Performance 348 nm AlGaN/GaN-Based Ultraviolet-Light-Emitting Diode with a SiN Buffer Layer , 2002 .

[2]  T. Egawa,et al.  Growth and characterization of high-quality quaternary AlInGaN epilayers on sapphire , 2003 .

[3]  M. Shur,et al.  Ultraviolet Light-Emitting Diodes at 340 nm using Quaternary AlInGaN Multiple Quantum Wells , 2001 .

[4]  K. H. Kim,et al.  III-nitride ultraviolet light-emitting diodes with delta doping , 2003 .

[5]  Yoon-Kyu Song,et al.  AlGaN/GaN quantum well ultraviolet light emitting diodes , 1998 .

[6]  X. Cheng,et al.  Growth, spectroscopic and thermal behavior of Cd(SCN)2(DMSO)2 , 2002 .

[7]  Tao Wang,et al.  Study of the strain relaxation in InGaN/GaN multiple quantum well structures , 2001 .

[8]  Naoki Kobayashi,et al.  Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN , 2001 .

[9]  Tao Wang,et al.  1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate , 2002 .

[10]  Manijeh Razeghi,et al.  High-power 280 nm AlGaN light-emitting diodes based on an asymmetric single-quantum well , 2004 .

[11]  Isamu Akasaki,et al.  Quantum-Confined Stark Effect due to Piezoelectric Fields in GaInN Strained Quantum Wells , 1997 .

[12]  Takashi Mukai,et al.  365 nm Ultraviolet Laser Diodes Composed of Quaternary AlInGaN Alloy , 2003 .

[13]  Petr G. Eliseev,et al.  BLUE TEMPERATURE-INDUCED SHIFT AND BAND-TAIL EMISSION IN INGAN-BASED LIGHT SOURCES , 1997 .

[14]  Tao Wang,et al.  Effect of silicon doping on the optical and transport properties of InGaN/GaN multiple-quantum-well structures , 2000 .

[15]  M. Shur,et al.  Pulsed atomic layer epitaxy of quaternary AlInGaN layers , 2001 .

[16]  Manijeh Razeghi,et al.  Top-emission ultraviolet light-emitting diodes with peak emission at 280 nm , 2002 .