摘要
PtS2, which is one of the group-10 transition metal dichalcogenides, attracts increasing attention due to its extraordinary properties under external modulations as predicted by theory, such as tunable bandgap and indirect-to-direct gap transition under strain; however, these properties have not been verified experimentally. Here we report the first experimental exploration of its optoelectronic properties under external pressure. We find that the photocurrent is weakly pressuredependent below 3 GPa but increases significantly in the pressure range of 3 GPa–4 GPa, with a maximum ～ 6 times higher than that at ambient pressure. X-ray diffraction data shows that no structural phase transition can be observed up to26.8 GPa, which indicates a stable lattice structure of PtS2 under high pressure. This is further supported by our Raman measurements with an observation of linear blue-shifts of the two Raman-active modes to 6.4 GPa. The pressure-enhanced photocurrent is related to the indirect-to-direct/quasi-direct bandgap transition under pressure, resembling the gap behavior under compression strain as predicted theoretically.
PtS2, which is one of the group-10 transition metal dichalcogenides, attracts increasing attention due to its extraordinary properties under external modulations as predicted by theory, such as tunable bandgap and indirect-to-direct gap transition under strain; however, these properties have not been verified experimentally. Here we report the first experimental exploration of its optoelectronic properties under external pressure. We find that the photocurrent is weakly pressuredependent below 3 GPa but increases significantly in the pressure range of 3 GPa–4 GPa, with a maximum ～ 6 times higher than that at ambient pressure. X-ray diffraction data shows that no structural phase transition can be observed up to26.8 GPa, which indicates a stable lattice structure of PtS2 under high pressure. This is further supported by our Raman measurements with an observation of linear blue-shifts of the two Raman-active modes to 6.4 GPa. The pressure-enhanced photocurrent is related to the indirect-to-direct/quasi-direct bandgap transition under pressure, resembling the gap behavior under compression strain as predicted theoretically.
作者
袁亦方
张志涛
王伟科
周永惠
陈绪亮
安超
张冉冉
周颖
顾川川
李亮
李新建
杨昭荣
Yi-Fang Yuan;Zhi-Tao Zhang;Wei-Ke Wang;Yong-Hui Zhou;Xu-Liang Chen;Chao An;Ran-Ran Zhang;Ying Zhou;Chuan-Chuan Gu;Liang Li;Xin-Jian Li;Zhao-Rong Yang(Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052, China;Anhui Provincial Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China;Synergetic Innovation Center for Quantum Effects and Application, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of Education, College of Physics and Information Science, Hunan Normal University, Changsha 410081, China;State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology （HUST）, Wuhan 430074, China;Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, China)
基金
supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0305700 and 2016YFA0401804)
the National Natural Science Foundation of China(Grant Nos.11574323,11704387,U1632275,11304321,11604340,and 61774136)
the Natural Science Foundation of Anhui Province,China(Grant No.1708085QA19)
the Director’s Fund of Hefei Institutes of Physical Science,Chinese Academy of Sciences(Grant No.YZJJ201621)
