Chen Yunxu, Liu Jinxin, Zeng Mengqi, Lu Fangyun, Lv Tianrui, Chang Yuan, Lan Haihui, Wei Bin, Sun Rong, Gao Junfeng, Wang Zhongchang, Fu Lei
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China.
Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian, 116024, China.
Nat Commun. 2020 Aug 7;11(1):3979. doi: 10.1038/s41467-020-17693-5.
Ultra-thin III-V semiconductors, which exhibit intriguing characteristics, such as two-dimensional (2D) electron gas, enhanced electron-hole interaction strength, and strongly polarized light emission, have always been anticipated in future electronics. However, their inherent strong covalent bonding in three dimensions hinders the layer-by-layer exfoliation, and even worse, impedes the 2D anisotropic growth. The synthesis of desirable ultra-thin III-V semiconductors is hence still in its infancy. Here we report the growth of a majority of ultra-thin III-V single crystals, ranging from ultra-narrow to wide bandgap semiconductors, through enhancing the interfacial interaction between the III-V crystals and the growth substrates to proceed the 2D layer-by-layer growth mode. The resultant ultra-thin single crystals exhibit fascinating properties of phonon frequency variation, bandgap shift, and giant second harmonic generation. Our strategy can provide an inspiration for synthesizing unexpected ultra-thin non-layered systems and also drive exploration of III-V semiconductor-based electronics.
超薄III-V族半导体具有诸如二维（2D）电子气、增强的电子-空穴相互作用强度和强偏振光发射等引人入胜的特性，一直被视作未来电子学领域的期望材料。然而，它们在三维空间中固有的强共价键阻碍了逐层剥离，更糟糕的是，还妨碍了二维各向异性生长。因此，理想的超薄III-V族半导体的合成仍处于起步阶段。在此，我们报告了通过增强III-V族晶体与生长衬底之间的界面相互作用，以实现二维逐层生长模式，从而生长出了大部分超薄III-V族单晶，涵盖了从超窄带隙到宽带隙半导体。所得的超薄单晶展现出了声子频率变化、带隙偏移和巨大二次谐波产生等迷人特性。我们的策略可为合成意想不到的超薄非层状体系提供启发，也能推动基于III-V族半导体的电子学探索。
