Band alignment engineering: ultrabroadband photodetection with SnX2 (X  =  S, Se)/ZnS heterostructures. (11th December 2019)

• Record Type: Journal Article
• Authors: Yu, Zhuo-Liang; Zhao, Yu-Qing; Liu, Biao; Yang, Jun-Liang; Cai, Meng-Qiu
• Is Part Of: Journal of physics. Volume 32:Number 11(2020)
• Publication Date: 2019-12-11
• Subjects: heterojunction -- ultrabroadband -- mid-infrared detection; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ab5b3d
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Ultrabroadband mid-frequency infrared photodetectors have important applications in surveillance, medical diagnosis, bioimaging and navigation aids. Thus, researchers hope to detect mid-infrared radiation with larger wavelength. However, due to the limitation of room temperature, it is difficult for these detectors to detect mid-infrared with 4 µ m or larger wavelength. Therefore, at room temperature, how to realize mid-infrared detection in a wide range has become an urgent problem to be solved. In this paper, the band structure of SnX2 (X = S, Se)/ ZnS and SnS2(1− ŋ ) Se2 ŋ / ZnS was studied by the density functional theory based first-principles methods. Under the specific stacking procedure, changing the of SnS2(1− ŋ ) Se2 ŋ, the band gap of heterojunctions can be continuously tuned from 0 to 0.97 eV. Amazingly, the band structure maintains the characteristics of a type-II heterojunction. The photodetection in our work is estimated for wavelengths from 1.2 µ m to 10 µ m, covering a wide wavelength range of mid-infrared. Such a wide range is considerable in current research. The characteristics of type-II band structure and the wide detection range imply that SnX2 / ZnS has great potential in mid-frequency infrared detection. Our work may provide some breakthroughs for the research of multiband photodetectors at room temperature.