[1] Wang Cheng, Xia Hai-ping, Feng Zhi-gang, Zhang Zhi-xiong, Jiang Dong-sheng, Zhang Jian, Sheng Qi-guo, Tang Qing-yang, He Shi-nan, Jiang Hao-chuan and Chen Bao-jiu, Optoelectronics Letters 12, 56 (2016).

[2] Y. F. Li, Y. Qu, Y. M. Sun, X. Y. Hou and H. J. Qi, Acta Photonica Sinica 36, 591 (2007). (in Chinese)

[3] Pan Cheng, Feng-jing Yang, Zi-zhong Zhou, Bo Huang, 0205Li-bo Wu and Ya-xun Zhou, Optoelectronics Letters 12, 340 (2016).

[4] Weijie Guo, Yujin Chen, Yanfu Lin, Xinghong Gong,Zundu Luo and Yidong Huang, Journal of Physics D: Applied Physics 41, 115409 (2008).

[5] N. Coluccelli, G. Galzerano, D. Parisi, M. Tonelli and P. Laporta, Optics Letters 33, 1951 (2008).

[6] Huiqiong Yan, Xiuqiong Chen, Huangwang Song, Xianghui Wang, Zaifeng Shi and Qiang Lin, Materials Letters 187, 101 (2017).

[7] Jiang Dong-sheng, Jiang Yong-zhang, Xia Hai-ping, Zhang Jia-zhong, Yang Shuo, Gu Xue-mei, Jiang Hao-chuan and Chen Bao-jiu, Optoelectronics Letters 11, 356 (2015).

[8] Wu Lei, Zhang Hai-ming, Zhang Jing-Jing, Guo Cong, Ji Zi-ye and Bai Xiao-gang, Journal of Optoelectronics·Laser 26, 2340 (2015). (in Chinese)

[9] Zheng Jian, Cheng Yin, Wu Zhong-qing, Zhou Wei-wei and Tang Mei-xiang, Journal of Optoelectronics·Laser 26, 1924 (2015). (in Chinese)

[10] I. M. Shmyt’ko and G. K. Strukova, Physics of the Solid State 51, 1907 (2009).

[11] Sana J., Cases R. and Alcala R., Journal of Non-Crystalline Solids 93, 377 (1987).

[12] Wang Peiyuan, Xia Haiping, Peng Jiangtao, Tang Lei and Hu Haoyang, Journal of Optoeletronics·Laser 24, 2143 (2013). (in Chinese)

[13] Cornacchia F., Palatella L. and Toencelli A., Journal of Physics and Chemistry of Solids 63, 197 (2002).

[14] Shuo Yang, Haiping Xia, Yongzhang jiang, Jiazhong Zhang, Yiwen Shi, Xuemei Gu, Jianli Zhang, Yuepin Zhang, Haochuan Jiang and Baojiu Chen, Journal of Alloys and Compounds 643, 1 (2015).

[15] Jing Xiong, Haiyan Peng, Pengchao Hu, Yin Hang and Lianhan Zhang, Journal of Physics D: Applied Physics 43, 185 (2010).