High-performance electron mobility and photoabsorption in Bi2O2Se nanoribbons

Abstract

Two-dimensional (2D) Bi2O2Se has attracted much attention as a promising candidate for electronic and optoelectronic applications. However, the transport and optical properties in Bi2O2Se nanoribbons (NRs) are not yet fully understood. In this work, by using first-principles calculations, the intrinsic carrier mobility (μ) and the optical absorption properties of Bi2O2Se NRs are investigated. In contrast to the dramatic deterioration of μ in graphene upon the formation of NRs, the magnitude of μ in Bi2O2Se NRs can reach up to 3600 cm2 V-1 s-1 at a width ranging from 3.3 to 4.5 nm, which is about ten times higher than its sheet counterpart. Such a high intrinsic electron mobility of Bi2O2Se NRs can be attributed to the weaker edge state perturbations due to external strain inherent in Bi2O2Se NRs. Moreover, in Bi2O2Se NRs, the optical absorption at the visible (2.4-3.1 eV) and ultraviolet (4.3 eV) region reaches 5%-10% and 19.2%, respectively. Furthermore, the optical absorption properties can be well tuned by the width of NRs. In addition, the relatively small stretching modulus ranging from 0.40 to 2.24 × 10-7 J/m and the moderate critical strain ranging from 0.04 to 0.14 guarantee its moderate flexibility and ductility. Our results indicate that width modulation provides a potential approach for improving the transport and optical properties of Bi2O2Se nanostructures.