Chikara ONODERA, Masaaki YOSHIDA¹, Tadayoshi SHOJI², and Tsunemasa TAGUCHI³

Electronic Engineering Course, Aomori Prefectural Towada Technical Senior High School, 215-1 Shimotai Sanbongi, Towada, Aomori 034-0001, Japan
¹Department of Electrical and Computer Engineering, Hachinohe National College of Technology, 16-1 Uwanotai, Tamonoki, Hachinohe, Aomori 039-1192, Japan
²Department of Electronics, Tohoku Institute of Technology, 35-1 Yagiyama Kasumi-cho, Taihaku-ku, Sendai 982-8577, Japan
³Department of Electrical and Electronic Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, Japan

(Received December 4, 2009; Accepted February 12, 2010)

We calculate optical gain coefficient and threshold current density in ZnS/MgBeZnS quantum wells (QWs) because ZnS/MgBeZnS QWs are useful for the fabrication of an ultraviolet laser on zinc-blende substrates. The threshold current density in a ZnS/MgBeZnS QW laser diode (LD) with a 10 nm ZnS active layer is calculated to be 1.63 kA/cm². By comparing the measured J_th in a CdZnSe/ZnSSe/ZnMgSSe QW LD with that calculated by us, it is expected that the threshold current density in ZnS/MgBeZnS QW LDs measured by experiment is larger than that calculated by our calculation method.

Key words: ZnS, Be-chalcogenide, ultraviolet laser, gain coefficient, thresold current density