Narrow-gap physical vapour deposition synthesis of ultrathin SnS1−xSex(0 ≤ x ≤ 1) two-dimensional alloys with unique polarized Raman spectra and high (opto)electronic properties
Narrow-gap physical vapour deposition synthesis of ultrathin SnS1−xSex(0 ≤ x ≤ 1) two-dimensional alloys with unique polarized Raman spectra and high (opto)electronic properties
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窄间隙物理气相沉积合成具有独特偏振拉曼光谱和高（光）电子性能的超薄SnS1≤xSex(0≤x≤1)二维合金
DOI：
10.1039/c8nr00856f
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发表时间：
2018
期刊：
影响因子：
6.7
通讯作者：
Jingbo Li
中科院分区：
文献类型：
--
作者：
Wei Gao;Yongtao Li;Jianhua Guo;Muxun Ni;Ming Liao;Haojie Mo;Jingbo Li
在这里，我们报告了通过窄隙物理气相沉积方法合成的SnS 1 −xSex合金纳米片。SnS 1 −xSex合金呈均匀的四边形，横向尺寸为5-80 μm，厚度为几纳米。借助X射线衍射、高分辨透射电子显微镜和偏振拉曼光谱分析，发现二维合金化纳米片具有明显的正交对称性和独特的面内各向异性。此外，2D合金场效应晶体管的制造，表现出单极p型半导体行为。这项研究还提供了一个教训，即合金通道的厚度在电流开/关比中起着主要作用，并且由于电容屏蔽效应，从大型SnS SnS 1 −xSex器件测量的2.10 × 102的高比率比先前报道的SnS，SnSe纳米片晶体管大两个数量级。在较薄的纳米片中也发现了明显增强的拉曼峰。此外，在405至808 nm的532 nm激光照射下，基于SnS0.5Se0.5的光电探测器显示出1.69 A W-1的最高响应率和40 ms的短响应时间。同时，获得了392%的最高外量子效率和3.96 × 104琼斯的最高探测率。希望，窄间隙合成技术为我们提供了一种改进的策略，以获得大的2D纳米片，其可能倾向于生长成更厚的层间货车范德华力，并且所获得的SnS 1 −xSex合金纳米片的增强的物理和（光）电性能证明了它们在未来多功能器件应用中的巨大潜力。
Here we report ultrathin SnS1−xSex alloyed nanosheets synthesized via a narrow-gap physical vapour deposition approach. The SnS1−xSex alloy presents a uniform quadrangle shape with a lateral size of 5–80 μm and a thickness of several nanometers. Clear orthorhombic symmetries and unique in-plane anisotropic properties of the 2D alloyed nanosheets were found with the help of X-ray diffraction, high resolution transmission electron microscopy and polarized Raman spectroscopy. Moreover, 2D alloyed field-effect transistors were fabricated, exhibiting a unipolar p-type semiconductor behavior. This study also provided a lesson that the thickness of the alloyed channels played the major role in the current on/off ratio, and the high ratio of 2.10 × 102 measured from a large ultrathin SnS1−xSex device was two orders of magnitude larger than that of previously reported SnS, SnSe nanosheet based transistors because of the capacitance shielding effect. Obviously enhanced Raman peaks were also found in the thinner nanosheets. Furthermore, the ultrathin SnS0.5Se0.5 based photodetector showed a highest responsivity of 1.69 A W−1 and a short response time of 40 ms under illumination of a 532 nm laser from 405 to 808 nm. Simultaneously, the corresponding highest external quantum efficiency of 392% and detectivity of 3.96 × 104 Jones were also achieved. Hopefully, the narrow-gap synthesis technique provides us with an improved strategy to obtain large ultrathin 2D nanosheets which may tend to grow into thicker ones for stronger interlayer van der Waals forces, and the enhanced physical and (opto)electrical performances in the obtained ultrathin SnS1−xSex alloyed nanosheets prove their great potential in the future applications for versatile devices.