Single-and few-layer 2H-SnS_(2)and 4H-SnS_(2) nanosheets for high-performance photodetection  

作　　者：Lin Wang Xinzhe Li Chengjie Pei Cong Wei Jie Dai Xiao Huang Hai Li 

机构地区：[1]Key Laboratory of Flexible Electronic(KLOFE)&Institute of Advanced Materials(IAM),Nanjing Tech University,Nanjing 211816,China

出　　处：《Chinese Chemical Letters》2022年第5期2611-2616,共6页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foun-dation of China(Nos.51832001,21571101 and 51322202);the Natural Science Foundation of Jiangsu Province in China(No.BK20161543);the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.15KJB430016).

摘　　要：The properties of two-dimensional(2D)materials are highly dependent on their phase and thickness.Various phases exist in tin disulfide(SnS_(2)),resulting in promising electronic and optical properties.Hence,accurately identifying the phase and thickness of SnS_(2)nanosheets is prior to their optoelectronic applications.Herein,layered 2H-SnS_(2)and 4H-SnS_(2)crystals were grown by chemical vapor transportation and the crystalline phase of SnS_(2)was characterized by X-ray diffraction,ultralow frequency(ULF)Raman spectroscopy and high-resolution transmission electron microscope.As-grown crystals were mechanically exfoliated to single-and few-layer nanosheets,which were investigated by optical microscopy,atomic force microscopy and ULF Raman spectroscopy.Although the 2H-SnS_(2)and 4H-SnS_(2)nanosheets have similar optical contrast on SiO_(2)/Si substrates,their ULF Raman spectra obviously show different shear and breathing modes,which are highly dependent on their phases and thicknesses.Interestingly,the SnS_(2)nanosheets have shown phase-dependent electrical properties.The 4H-SnS_(2)nanosheet shows a current on/off ratio of 2.58×10^(5) and excellent photosensitivity,which are much higher than those of the 2H-SnS_(2)nanosheet.Our work not only offers an accurate method for identifying single-and few-layer SnS_(2)nanosheets with different phases,but also paves the way for the application of SnS_(2)nanosheets in highperformance optoelectronic devices.

关 键 词：Tin disulfide 2H and 4H phases Phase-dependent behavior Ultralow-frequency Raman spectroscopy PHOTODETECTION 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TN15[电子电信—物理电子学]