Salt-Assisted Low-Temperature Growth of 2D Bi2 O2 Se with Controlled Thickness for Electronics

Usman Khan; Adeela Nairan; Karim Khan; Sean Li; Bilu Liu; Junkuo Gao

doi:10.1002/smll.202206648

Salt-Assisted Low-Temperature Growth of 2D Bi₂ O₂ Se with Controlled Thickness for Electronics

Small. 2023 Mar;19(10):e2206648. doi: 10.1002/smll.202206648. Epub 2022 Dec 20.

Authors

Usman Khan^{1

2}, Adeela Nairan^{1

2}, Karim Khan³, Sean Li⁴, Bilu Liu⁵, Junkuo Gao^{1

2}

Affiliations

¹ Institute of Functional Porous Materials, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou, 310018, P. R. China.
² Zhejiang Provincial Innovation Center of Advanced Textile Technology, Shaoxing, 312000, P. R. China.
³ School of Electrical Engineering & Intelligentization, Dongguan University of Technology, Dongguan, 523808, P. R. China.
⁴ School of Materials Science and Engineering, The University of New South Wales, Sydney, 2052, Australia.
⁵ Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute & Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China.

PMID: 36538737
DOI: 10.1002/smll.202206648

Abstract

Bi₂ O₂ Se 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 Bi₂ O₂ Se at low-growth temperature. Here, a low-temperature salt-assisted chemical vapor deposition approach for growing single-domain Bi₂ O₂ Se 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 Bi₂ O₂ Se from monolayer to bulk is investigated, revealing a redshift of the A_1g mode at 162.4 cm^-1 . Moreover, the long-term environmental stability of ≈2.4 nm thick Bi₂ O₂ Se is confirmed after exposing the sample for 1.5 years to air. The backgated field effect transistor (FET) based on a few-layered Bi₂ O₂ Se flake represents decent carrier mobility (≈287 cm² V^-1 s^-1 ) and an ON/OFF ratio of up to 10⁷ . This report indicates a technique to grow large-domain thickness controlled Bi₂ O₂ Se single crystals for electronics.

Keywords: 2D materials; Bi 2O 2Se, field-effect transistors; millimeter-size single crystals; salt-assisted chemical vapor deposition (CVD); stability.

Abstract

Grants and funding