The emerging two-dimensional(2D)platinum disulfide(PtS_(2))has driven increasing attentions due to its high electron mobility,good air-stability,and strong interlayer interaction which leads to a widely tunable electr...The emerging two-dimensional(2D)platinum disulfide(PtS_(2))has driven increasing attentions due to its high electron mobility,good air-stability,and strong interlayer interaction which leads to a widely tunable electronic structure.However,a detailed study on its covalent-like layer-dependent properties remains infant.Herein,we demonstrate the successful production of ultrathin 1T-PtS_(2) ribbons with thickness centralized almost at monolayer 1L-4L and large domain size up to 210 μm on Au foils using chemical vapor deposition(CVD)technique,which enables macro-and microscopic study of its extraordinary layer-dependent features with precise control of the number of layers.Using electron energy loss spectroscopy(EELS)and optical pump-probe spectroscopy(OPPS),we reveal that both the electron and ultrafast optical absorption signals of the as-grown 2D PtS_(2) show strong nonlinear layer-dependent responses which manifest discriminated transition in 1L-4L PtS_(2) ribbons.The layer-dependent nonlinear response of 2D PtS_(2) can be well interpreted in the frame of calculated electron and phonon structures.These achievements offer a platform for successfully fabricating large-sized ultrathin 2D PtS_(2) and facilitating our knowledge about its electronic and optoelectronic properties.展开更多
基金The work was supported by the National Natural Science Foundation of China(Nos.51991344,51991340,11774354,51727806,61988102,11974156,12174398,and 12104206)Guangdong International Science Collaboration Project(No.2019A050510001)+2 种基金Guangdong Innovative and Entrepreneurial Research Team Program(No.2019ZT08C044)Shenzhen Science and Technology Program(Nos.KQTD20190929173815000 and 20200925161102001)the Science,Technology and Innovation Commission of Shenzhen Municipality(No.ZDSYS20190902092905285)。
文摘The emerging two-dimensional(2D)platinum disulfide(PtS_(2))has driven increasing attentions due to its high electron mobility,good air-stability,and strong interlayer interaction which leads to a widely tunable electronic structure.However,a detailed study on its covalent-like layer-dependent properties remains infant.Herein,we demonstrate the successful production of ultrathin 1T-PtS_(2) ribbons with thickness centralized almost at monolayer 1L-4L and large domain size up to 210 μm on Au foils using chemical vapor deposition(CVD)technique,which enables macro-and microscopic study of its extraordinary layer-dependent features with precise control of the number of layers.Using electron energy loss spectroscopy(EELS)and optical pump-probe spectroscopy(OPPS),we reveal that both the electron and ultrafast optical absorption signals of the as-grown 2D PtS_(2) show strong nonlinear layer-dependent responses which manifest discriminated transition in 1L-4L PtS_(2) ribbons.The layer-dependent nonlinear response of 2D PtS_(2) can be well interpreted in the frame of calculated electron and phonon structures.These achievements offer a platform for successfully fabricating large-sized ultrathin 2D PtS_(2) and facilitating our knowledge about its electronic and optoelectronic properties.
