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Molecular Beam Epitaxy and Electronic Structure of Atomically Thin Oxyselenide Films
Author(s) -
Liang Yan,
Chen Yujie,
Sun Yuanwei,
Xu Shipu,
Wu Jinxiong,
Tan Congwei,
Xu Xiaofeng,
Yuan Hongtao,
Yang Lexian,
Chen Yulin,
Gao Peng,
Guo Jiandong,
Peng Hailin
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201901964
Subject(s) - molecular beam epitaxy , materials science , monolayer , angle resolved photoemission spectroscopy , substrate (aquarium) , thin film , band gap , photoemission spectroscopy , semiconductor , nanotechnology , optoelectronics , electronic structure , epitaxy , x ray photoelectron spectroscopy , condensed matter physics , layer (electronics) , chemical engineering , physics , oceanography , geology , engineering
Atomically thin oxychalcogenides have been attracting intensive attention for their fascinating fundamental properties and application prospects. Bi 2 O 2 Se, a representative of layered oxychalcogenides, has emerged as an air‐stable high‐mobility 2D semiconductor that holds great promise for next‐generation electronics. The preparation and device fabrication of high‐quality Bi 2 O 2 Se crystals down to a few atomic layers remains a great challenge at present. Here, molecular beam epitaxy (MBE) of atomically thin Bi 2 O 2 Se films down to monolayer on SrTiO 3 (001) substrate is achieved by co‐evaporating Bi and Se precursors in oxygen atmosphere. The interfacial atomic arrangements of MBE‐grown Bi 2 O 2 Se/SrTiO 3 are unambiguously revealed, showing an atomically sharp interface and atom‐to‐atom alignment. Importantly, the electronic band structures of one‐unit‐cell (1‐UC) thick Bi 2 O 2 Se films are observed by angle‐resolved photoemission spectroscopy (ARPES), showing low effective mass of ≈0.15 m 0 and bandgap of ≈0.8 eV. These results may be constructive to the synthesis of other 2D oxychalcogenides and investigation of novel physical properties.