研究概述

在半导体物理学及相关器件领域，识别出兼具高载流子迁移率和较大电子带隙的新型2D材料至关重要，这些材料在突破传统半导体(如硅和GaAs)所不及的极薄极限方面具有巨大潜力。然而，迄今为止，能够在空气中保持稳定并拥有卓越性能的极薄半导体材料仍难以实现。最近，彭研究团队成功实现了高迁移率半导体2D晶体的可控合成--层状铋氧硫化物(BOX，Bi202X:X=S、Se、Te)。他们正积极探索此类材料在电子和光电子学领域的应用前景。彭研究团队对化学气相沉积(CVD)以及外延生长大尺寸二维层状Bi202Se单晶体(厚度可低至单层)感兴趣。此类晶体表现出优异的空气稳定性、约0.14m0的低电有效质量以及可调的带隙值(约0.8eV)。二维BOX晶体可被加工成高性能场效应晶体管和近红外(NIR)光电探测器，其中还观测到了显著的量子振荡现象。

In semiconductor physics and related devices, it is pivotal to identify new 2D materials with both high carrier mobility and large electronic bandgap, which hold great promises in pushing the ultrathin limitation where the traditional semiconductors (e.g. Si and GaAs) fall short. However, air-stable ultrathin semiconducting materials with superior performances remain elusive up to date. Very recently, the Peng research group realized the controlled syntheses of high-mobility semiconducting 2D crystals--- layered bismuth oxychalcogenides (BOX, Bi2O2X: X = S, Se, Te), and are vigorously exploring their vistas in electronics and optoelectronics. The Peng research group is interested in chemical vapor deposition (CVD) and epitaxial growth of large-area layered Bi2O2Se single crystals with the thickness down to monolayer, which exhibit excellent air-stability, low electron effective mass of ~0.14 m0, and tunable bandgap values of ~ 0.8 eV. 2D BOX crystals can be fabricated into high-performance field-effect transistors and near-infrared (NIR) photodetectors, where pronounced quantum oscillations were also observed.