Optical and defect properties of S-doped and Al-doped GaSe crystals
Huang Chang-Bao, WuWu Hai-Xin †, Ni You-Bao, Wang Zhen-You, Chen Shi-Jing
       

(color online) (a) Photograph of pure, S-doped, and Al-doped GaSe crystals (b) and their XRD patterns.