Anisotropic optical property of ferroelectric Bi2O2X(X = S,Se,Te) monolayer and strain engineering

Miao Yu; Wei Xun; Yaojun Dong; Han Gu; Jia-Lin Zhong; Jie Ren; Xiang Hao; Yin-Zhong Wu

doi:10.1088/1361-648X/ad4add

Anisotropic optical property of ferroelectric Bi₂O₂X(X = S,Se,Te) monolayer and strain engineering

J Phys Condens Matter. 2024 May 23;36(33). doi: 10.1088/1361-648X/ad4add.

Authors

Miao Yu¹, Wei Xun², Yaojun Dong³, Han Gu³, Jia-Lin Zhong^{4

5}, Jie Ren³, Xiang Hao¹, Yin-Zhong Wu¹

Affiliations

¹ Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, and School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China.
² School of Electrical Engineering, Jiangsu Vocational College of Electronics and Information, Huaian 223003, People's Republic of China.
³ School of Electronic and Information Engineering, Changshu Institute of Technology, Changshu 215500, People's Republic of China.
⁴ School of Electronic and Information Engineering, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China.
⁵ Semiconductor Sensor and Microelectronic system TEKISM United Laboratory, Suzhou 215009, People's Republic of China.

PMID: 38740061
DOI: 10.1088/1361-648X/ad4add

Abstract

Based on the first-principles calculations, ferroelectricBi2O2X(X=S,Se,Te)monolayers with unequivalent in-plane lattice constants are confirmed to be the ground state, which is consistent with the experiment result (Ghoshet al2019Nano Lett.195703-09), and the anisotropic optical property is firstly investigated. We find that the polarizations ofBi2O2Xmonolayers points along the direction ofa-axis, andBi2O2Temonolayer process the largest polarization. Furthermore, both the biaxial and uniaxial strains are favor for the enhancement of polarization ofBi2O2Xmonolayers. It should be mentioned that the type of band gap will convert from indirect to direct forBi2O2Temonolayer when thea-axial tensile strain is larger than 2%. At last, the optical absorption coefficient forBi2O2Xmonolayers are calculated, and we obtain thatBi2O2Temonolayer has the strongest optical absorption within the range of visible light, the anisotropy and possible strain engineering to improve the optical absorption are discussed in detail. Our findings are significant in fields of optoelectronics and photovoltaics.

Keywords: Bi2O2X(X = S,Se,Te) monolayer; ferroelectricity; optical property; strain engineering.