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

Ti Wang, G. Raviprakash, F. Ranalli, C. N. Harrison, Jie Bai, J. P. R. David, P. J. Parbrook, Jin‐Ping Ao, Yasuhide Ohno

Journal of Applied Physics · 2005 · 13 citations · 16 references

Concepts

Abstract

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.

References

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