Twist angle and electric gating controllable electronic structure of the two-dimensional stacked BP homo-structure

• Published in: Physical chemistry chemical physics : PCCP 2023-12, Vol.26 (1), p.23-24
• Main Authors: Yao, Linwei, Yun, Jiangni, Kang, Peng, Zhao, Hongyuan, Zhang, Siyu, Zeng, Liru, Bi, Zhisong, Yan, Junfeng, Zhao, Wu, Zhang, Zhiyong
• Format: Article
• Language: English
• Subjects: Bilayers; Boron phosphides; Carrier mobility; Controllability; Density functional theory; Electric fields; Electronic properties; Electronic structure; Energy gap; Excitons; High resistance; Mathematical analysis; Optoelectronic devices; Photoelectric effect; Photoelectricity; Stark effect
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d3cp03591c

The boron phosphide (BP) van der Waals (vdW) homostructure is designed to construct high-performance nano-optoelectronic devices due to its distinctive photoelectric properties. Using density functional theory, the electronic properties of twisted and untwisted BP bilayer structures are systematically calculated. We found that the 0° structure is a direct band gap semiconductor with a type II band alignment, the carrier mobility of which is increased to 10 4 , and its photoelectric conversion efficiency is 17.3%. By analyzing the band structure and exciton binding energy calculated at 0° under an electric field, it is further found that 0° is a superior photoelectric material. As for the twist BP bilayer, the band gap changes with torsional structures under the applied electric field, which generates the Stark effect. The twist angles of bilayer BP, specifically 13.17°, 21.79°, 38.21°, and 46.83°, always maintain a direct band gap under the influence of an electric field. While 60° is an indirect band gap, the structure exhibits high resistance to the electric field. Our results reveal that bilayer BP is a potential application prospect in photovoltaic and optoelectronic fields and can provide more insights into optoelectronic devices. The direct band semiconductor AB_B-P can be arranged as a type-II semiconductor. After the corner changes, there are modifications in the electronic structure's response to the external electric field.