Salt‐Assisted Low‐Temperature Growth of 2D Bi₂O₂Se with Controlled Thickness for Electronics

Abstract

Bi2O2Se is the most promising 2D material due to its semiconducting feature and high mobility, making it propitious channel material for high‐performance electronics that demands highly crystalline Bi2O2Se at low‐growth temperature. Here, a low‐temperature salt‐assisted chemical vapor deposition approach for growing single‐domain Bi2O2Se on a millimeter scale with thicknesses of multilayer to monolayer is presented. Because of the advantage of thickness‐dependent growth, systematical scrutiny of layer‐dependent Raman spectroscopy of Bi2O2Se from monolayer to bulk is investigated, revealing a redshift of the A1g mode at 162.4 cm−1. Moreover, the long‐term environmental stability of ≈2.4 nm thick Bi2O2Se is confirmed after exposing the sample for 1.5 years to air. The backgated field effect transistor (FET) based on a few‐layered Bi2O2Se flake represents decent carrier mobility (≈287 cm2 V−1s−1) and an ON/OFF ratio of up to 107. This report indicates a technique to grow large‐domain thickness controlled Bi2O2Se single crystals for electronics.

A hidden phase uncovered by ultrafast carrier dynamics in thin Bi2O2Se

“…In contrast to van der Waals (vdW) forces, Bi 2 O 2 Se exhibits relatively strong electrostatic forces between layers due to its alternately stacked positively charged [Bi 2 O 2 ] 2+ and negatively charged Se 2− layers along the c direction. 1,2 With a moderate bandgap ranging from 0.8 eV to 2.09 eV 3,4 and a high mobility of 28 900 cm 2 V −1 s −1 at 1.9 K and 450 cm 2 V −1 s −1 at room temperature, 5,6 along with high thermal and chemical stability, 4,7 Bi 2 O 2 Se holds great promise as a candidate for next-generation electronics, 8,9 optoelectronics, 7,10,11 thermoelectrics, 12,13 and ferroelectrics. 14,15 Furthermore, developing controllable large-area and high-quality 2D Bi 2 O 2 Se films speeds up the applications.…”

“…14,15 Furthermore, developing controllable large-area and high-quality 2D Bi 2 O 2 Se films speeds up the applications. 7,10 Given the high demand for data storage, extensive research has focused on the ferroelectric properties of Bi 2 O 2 Se. [16][17][18] Ghosh et al reported the presence of ferroelectricity in 2 nm single-crystalline Bi 2 O 2 Se nanosheets through dielectric measurements and piezoresponse force spectroscopy.…”

“…The characteristic peaks observed at 159 cm −1 to 156 cm −1 can be attributed to the A 1g vibrational mode of Bi 2 O 2 Se flakes, 25 while the peak at 195.9 cm −1 in the thinner films originates from the mica substrate, as indicated by the dashed lines. 7 It is worth noting that the mica peak is only visible in the thinner films. Through Lorentz fitting, we obtained the A 1g phonon frequency and width as a function of film thickness, as depicted in Fig.…”

Recent advances in MXenes: a future of nanotechnologies

“…M n +1 X n T x ( n = 1 to 4) is a common formula for 2D MXene NMs, where M indicates transition metals (TMs) 3,5,6,13,20,49–80 and X indicates carbon or nitrogen, respectively 1,7–10,15,16,18,23,25,35,81–126 . Also, T x (where x varies) denotes single or mixed termination groups (for example, T = S, O, NH, F, Cl, Br, Te, OH, Se), as shown in Fig.…”

Theoretical Tuning of the Cu/S Ratio on Two-Dimensional CuSx Materials for the CO2 Electrochemical Reduction Reaction

“…Two-dimensional (2D) materials have attracted considerable attention as interesting candidates for numerous applications since the discovery of graphene. , Theoretical studies and experimental studies have contributed to expand the number of known 2D materials and improve our atomistic understanding of their electronic, , optical, , and structural properties. , The use of 2D materials in catalysis has emerged as a natural application due to the high surface area-to-volume ratio and the potential to tune their properties through defect engineering . For example, 2D materials have been employed as catalysts for diverse chemical reactions, including but not limited to the oxygen reduction reaction (ORR), , hydrogen evolution reaction (HER), , and oxygen evolution reaction (OER). , …”