Electronic Structures and Lattice Dynamics of Layered BiOCl Single Crystals

Abstract

BiOCl has recently elicited intense interest for its excellent photochemical catalysis, energy conversion, and photodetection performance. In this Letter, we systematically investigate BiOCl electronic properties, lattice dynamics, and structural stability. From first-principles calculations, bulk and monolayer BiOCl have ultraviolet indirect band gaps around 3.6 eV, consistent with reflection spectroscopy measurements. The large spin−orbit coupling effect of the Bi atom makes the lowest conduction band near the Z point in the Brillouin region move down 230 meV. However, because of the symmetrical crystal potential, BiOCl has no strong Rashba effect. We further observed all 6 BiOCl Raman-active modes with the lowest-frequency rigid layer in-plane vibrational mode at 63 cm −1 , consistent with our calculations. Up to 500 K or down to monolayer thickness, the crystal structure of BiOCl remains stable. Our work provides detailed information on BiOCl electronic and vibrational properties and stability up to high temperature or down to monolayer, identifying it as a promising layered material for further nano-optoelectronic applications.

Identification of two-dimensional layered dielectrics from first principles

“…We report the HSE and PBE band gap values along with the electron affinity values in Supplementary Table 4 . Even larger predicted G 0 W 0 band gaps obtained from other theoretical studies 50 along with experimental band gaps for some 2D monolayers 51 , 52 are included in Table S5 . A good dielectric candidate material must have a band offset exceeding 1 eV with the channel material to minimize leakage current caused by Schottky emission of carriers into the dielectric 53 .…”

Differences and Similarities of Photocatalysis and Electrocatalysis in Two-Dimensional Nanomaterials: Strategies, Traps, Applications and Challenges

“…The electronic properties and lattice dynamics of this material have been reported, and the layered crystal structure is illustrated in Fig. 4 g, where the Bi and O atom layers are sandwiched between the Cl atom layers [ 275 ].…”

All-Printed Dielectric Capacitors from High-Permittivity, Liquid-Exfoliated BiOCl Nanosheets

“…Each sheet consists of alternating layers of Cl − , Bi 3+ , and O 2− ions, as shown in Figure 1A. 23 It is found as a lustrous white material and in our case was purchased as a white powder. Scanning electron microscopy (SEM) imaging of the unexfoliated powder shows the presence of layered structures (Figure 1B).…”

“…Bismuth oxychloride (BiOCl) is an inorganic layered material, which has been used since ancient times, primarily in cosmetics. Each sheet consists of alternating layers of Cl – , Bi 3+ , and O 2– ions, as shown in Figure A . It is found as a lustrous white material and in our case was purchased as a white powder.…”