Search for content and authors

Stimulated emission in InGaN/GaN structures with different quantum well width

Saulius Miasojedovas 1Saulius Jursenas 1Genadij KurilĨik 1Arturas Zukauskas 1Shih-Wei Feng 2Yung-Chen Cheng 2C.C. Yang 2Cheng-Ta Kuo 3Jian-Shihn Tsang 3

1. Institute of Materials Science and Applied research (IMSAR), Sauletekio al. 9, Vilnius 2040, Lithuania
2. Graduate Institute of Electro-Optical Engineering and Department of Electrical Engineering, National Taiwan University 1, Roosevelt Road, Sec. 4, Taipei, Taiwan
3. Advanced Epitaxy Technology Inc., Hsinchu Industrial Park, Hsinchu, Hsinchu, Taiwan


Light-emitting and laser diodes for green to near-UV region are based on quantum structures with InGaN active region. However, characteristics of devices with multiple quantum wells (MQWs) are not clear so far. One of the most important characteristics of MQWs is the well width. With increasing the well width the emission from MQWs is affected not only by quantum confinement, but by intricate processes due to spinodal decomposition of In and built-in electrical field as well. To maximise spontaneous and stimulated emission, underlying physics should be cleared out and the growth conditions and structure of the MQWs are to be optimised.
Here we present results on high-excitation luminescence spectroscopy in In0.15Ga0.85N/GaN MQWs with various well width. High excitation conditions results in screening of built-in electrical field by free carriers and allowed us to determine the influence of In segregation on optical properties. Optimal quantum well thickness for InGaN/GaN lasing structures is obtained for the well width d = 3 nm. With increasing the well thickness, indium-rich clusters increase in size that results in an occurrence of deeper localization states with longer depopulation time and conventional degradation of the material. Meanwhile in thin wells, increased role of the interfaces states results in enhanced nonradiative recombination.


Legal notice
  • Legal notice:

Related papers

Presentation: poster at E-MRS Fall Meeting 2003, Symposium A, by Saulius Miasojedovas
See On-line Journal of E-MRS Fall Meeting 2003

Submitted: 2003-05-20 16:17
Revised:   2009-06-08 12:55