Heterostructures constructed by two-dimensional(2D)material layers,which are usually prepared via a transfer/stacking method or van der Waals epitaxy,have achieved significant success in various optoelectronic devices...Heterostructures constructed by two-dimensional(2D)material layers,which are usually prepared via a transfer/stacking method or van der Waals epitaxy,have achieved significant success in various optoelectronic devices including solar cells,light-emitting diodes and photodetectors.However,to date,most of these heterostructures comprise 2D materials with a similar crystal structure.Thus,preparation of heterostructures with different crystal structures is desirable but still a great challenge.Herein,we report a one-step CVD strategy to successfully grow SnS_(2)/SnS vertical heterostructures on a mica substrate.Raman spectroscopy,atomic force microscopy(AFM)and transmission electron microscopy(TEM)characterizations reveal that the heterostructure is formed by stacking of pyramid-shaped SnS_(2)of the hexagonal structure onto the rhombus SnS flake of the orthorhombic structure.The photodetector based on the SnS_(2)/SnS heterostructure demonstrates high optoelectronic performance:a 27.7 A W^(-1)photoresponsivity,2.2×10^(3)on/off ratio,less than 10 ms response time and 2.1×10^(10)jones specific detectivity.The superior performance originates from the high crystal quality of the as-grown heterostructure and its vertical device architecture.This study can expand our capability to fabricate a variety of two-dimensional heterostructures and make these heterostructures highly desirable as novel building blocks for potential applications in electronic and optoelectronic devices.展开更多
基金financial supports received from MOST of China(2016YFA0200602)the National Natural Science Foundation of China(21421063,11474260,11374274,11504364)+1 种基金the Chinese Academy of Sciences(XDB01020200)the Anhui Natural Science Foundation(1608085QA17).
文摘Heterostructures constructed by two-dimensional(2D)material layers,which are usually prepared via a transfer/stacking method or van der Waals epitaxy,have achieved significant success in various optoelectronic devices including solar cells,light-emitting diodes and photodetectors.However,to date,most of these heterostructures comprise 2D materials with a similar crystal structure.Thus,preparation of heterostructures with different crystal structures is desirable but still a great challenge.Herein,we report a one-step CVD strategy to successfully grow SnS_(2)/SnS vertical heterostructures on a mica substrate.Raman spectroscopy,atomic force microscopy(AFM)and transmission electron microscopy(TEM)characterizations reveal that the heterostructure is formed by stacking of pyramid-shaped SnS_(2)of the hexagonal structure onto the rhombus SnS flake of the orthorhombic structure.The photodetector based on the SnS_(2)/SnS heterostructure demonstrates high optoelectronic performance:a 27.7 A W^(-1)photoresponsivity,2.2×10^(3)on/off ratio,less than 10 ms response time and 2.1×10^(10)jones specific detectivity.The superior performance originates from the high crystal quality of the as-grown heterostructure and its vertical device architecture.This study can expand our capability to fabricate a variety of two-dimensional heterostructures and make these heterostructures highly desirable as novel building blocks for potential applications in electronic and optoelectronic devices.
