Effect of S Vacancy and Interlayer Interaction on the Electronic and Optical Properties of MoS2/WSe2 Heterostructure

• Published in: Journal of electronic materials 2023-02, Vol.52 (2), p.1186-1192
• Main Authors: Zhen, Xuan, Liu, Huating, Liu, Fei, Zhang, Shenrui, Zhong, Jianxin, Huang, Zongyu
• Format: Article
• Language: English
• Subjects: Absorptivity; Characterization and Evaluation of Materials; Chemistry and Materials Science; Conduction bands; Defects; Electric fields; Electromagnetic absorption; Electronic structure; Electronics and Microelectronics; First principles; Heterostructures; Instrumentation; Interlayers; Materials Science; Mathematical analysis; Molybdenum disulfide; Near infrared radiation; Optical and Electronic Materials; Optical properties; Optoelectronic devices; Original Research Article; Solid State Physics; Transition metal compounds
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-022-10055-5

The van der Waals (vdWs) heterostructure retains some excellent properties of monolayer transition metal dichalcogenides (TMDs), and has a significant improvement in performance, which is anticipated to play an important role in optoelectronic devices. S vacancy and interlayer interaction act together to influence the properties of the system. In this work, based on first-principles calculations, the effect of S vacancy on the electronic and optical properties of the MoS 2 /WSe 2 heterostructure were investigated. The calculation demonstrated that a single S vacancy introduces defect states between the conduction band minimum (CBM) and the Fermi level. For optical properties, the formed, built-in electric field of a heterostructure would prevent electron and hole recombination. Both systems show strong light absorption in the visible and ultraviolet regions. The absorption coefficient in the infrared regions of the defected MoS 2 /WSe 2 heterostructure was larger than that of the perfect heterostructure. The defect states were influenced by interlayer distance. The defected MoS 2 /WSe 2 heterostructure experienced a direct-gap semiconductor to metal, and the band gap decreased with decreasing layer distance. Also, all the systems showed strong light absorption in the visible and ultraviolet regions. As for the near-infrared region, light absorption of the defected MoS 2 /WSe 2 heterostructure was more obvious as the interlayer distance decreased, while the smaller the layer distance, the more obvious was the absorption in the near-infrared region. In summary, S vacancy and interlayer interaction have important effects on the electronic structure and optical properties of the MoS 2 /WSe 2 heterostructure, which is helpful for the design of multifunctional high-performance optoelectronic devices.