Investigation of Electronic and Optical Properties of (Cs, Br, Cs-Br) Doped Mono-Layer Hexagonal Boron Nitride Using First Principles

• Published in: Crystals (Basel) Vol. 12; no. 10; p. 1406
• Main Authors: Fu, Yangchen, Zhang, Wenchao, Fan, Zhihua, Jiang, Hongcheng, Hou, Yuhang, Luo, Qiuyu, Wang, Yi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-10-2022
• Subjects: Absorption; Accuracy; Approximation; band gap; Boron; Boron nitride; Chemical bonds; co-doping; Communication; Doping; Electric properties; Electronic structure; Energy; Energy gap; First principles; Frequencies; Graphene; Investigations; Mathematical analysis; mono-layer hexagonal boron nitride; Monomolecular films; Optical properties; Photoelectric effect; Photoelectricity; Semiconductors; China
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst12101406

Research on the effect of alternative doping on the photoelectric properties of boron nitride is still at an early stage. In particular, research on hexagonal boron nitride’s diatomic co-doping is still rarely studied. In this work, first-principles calculations are selected as the main method to investigate the electronic structure and optical properties of different atoms used to dope hexagonal boron nitride (h-BN). The band gap value of intrinsic h-BN is 4.66 eV. The band gap was changed after Cs, Br, and Cs-Br doping. The results show that the band gap is 4.61 eV when the Br atom replaces the N atom, while the band gap of h-BN doped with Cs is 3.52 eV. Additionally, the band gap width can be reduced to a typical narrower band gap width of 3.19 eV when Cs-Br is used for doping. At the same time, the complex dielectric function representing the optical properties is calculated after Cs, Br, and Cs-Br doping. The optical absorption peaks of Cs-Br-doped h-BN are weaker at low-frequency conditions. The optical absorption of h-BN can be modified by Cs doping, Br doping, and Cs-Br co-doping in the near-infrared, visible, or portion of the near-ultraviolet bands, which makes the doped material more suited for photoelectric detectors in the relevant frequency bands.