[1] E. F. Schubert, Light-Emitting Diodes, Cambridge Univ.Press, UK, 2003.
[2] D. A. Steigerwald, J. C. Bhat, D. Collins, R. M. Fletcher, M.O. Holcomb, M. J. Ludowise, P. S. Martin and S. L. Rudaz,IEEE J. Sel. Top. Quantum Electron 8, 310 (2002).
[3] J. Kim, S. Somani and Y. Yamamoto, Nonclassical Light from Semiconductor Lasers and LEDs, Spinger, 2001.
[4] S. Nakamura, T. Mukai and M. Senoh, Appl. Phys. Lett. 64,1687 (1994).
[5] M. G. Craford, N. Holonyak and F. A. Kish, Sci. Am. 284,63 (2001).
[6] Y. Narukawa, Opt. Photonics News 15, 24 (2004).
[7] A. Bergh, G. Craford, A. Duggal and R. Haiz, Phys. Today 54, 42 (2001).
[8] I. Moreno, C-C. Sun and R. Ivanov, Appl. Opt. 48, 1190 (2009).
[9] Z. Guo, Y. Gao, Y. Lu.., Y. Lin, H. Chen, R. Lei, Y. Chen and Z. Chen, Journal of Optoelectronics..Laser 22, 992 (2011).(in Chinese)
[10] M. Peeters, G. Verschaffelt, H. Theinpont, S. K. Mandre, I.Fischer and M. Grabherr, Opt. Express 13, 9337 (2005).
[11] M. Peeters, G. Verschaffelt, J. Speybrouck, H. Theinpont, J.Danckaert, J. Turunen and P. Vahimaa, Opt. Lett. 31, 1178(2006).
[12] F. J. Duarte, L. S. Liao and K. M. Vaeth, Opt. Lett. 30, 3072 (2005).
[13] F. J. Duarte, Opt. Lett. 32, 412 (2007).
[14] D. S. Mehta, K. Saxena, S. K. Dubey and C. Shakher, Journal of Luminescence 130, 96 (2010).
[15] M. Born and E. Wolf, Principles of Optics, Cambridge Univ.Press, UK, 1999.
[16] MENG Zhuo, LIANG Yu, YAO Xiao-tian, YAO Hui, LIUTie-gen and WAN Mu-sen, Journal of Optoelectronics..Laser 22, 256 (2011). (in Chinese)
[17] Z. Chen, L. Hua and J. Pu, Prog. Opt. 57, 219 (2012).
