In situ tracking anisotropic photocarrier dynamics in two-dimensional ternary Ta_(2)NiSe_(5) via digital micromirror device-based pump-probe microscopy  

作　　者：BINGXU CHEN JIE QIAO FEI HAN FU FENG SHIH-CHI CHEN 

机构地区：[1]Department of Mechanical and Automation Engineering,The Chinese University of Hong Kong,Hong Kong,China [2]Zhejiang Lab,Research Center for Humanoid Sensing,Hangzhou 311100,China

出　　处：《Photonics Research》2024年第9期1918-1926,共9页光子学研究（英文版）

基　　金：Research Grants Council,University Grants Committee(14209421);InnoHK Centre projects funded by the Innovation and Technology Commission(COCHE1.5);Science,Technology and Innovation Commission of Shenzhen Municipality(SGDX2020110309500100);Center-initiated Research Project of Zhejiang Lab(113014-AL2209);Natural Science Foundation of Zhejiang Province(LQ23F050009);National Natural Science Foundation of China(61905147,62205215,62275167).

摘　　要：In two-dimensional(2D)material studies,tracking the anisotropic ultrafast carrier dynamics is essential for the development of optoelectronic nano-devices.Conventionally,the anisotropic optical and electronic properties are investigated via either polarization-dependent Raman spectroscopy or field-effect transistors measurements.However,study of the anisotropic transient carrier behaviors is still challenging,due largely to the lack of picosecond-resolved acquisition or programmable scanning capabilities in the current characterization systems.In this work,we select Ta_(2)NiSe_(5) as a model system to investigate the ultrafast anisotropic transportation properties of photo-excited carriers and transient polarized responses via a digital micromirror device(DMD)-based pumpprobe microscope,where the probe beam scans along the armchair and zigzag directions of a crystal structure via binary holography to obtain distinct carrier diffusion coefficients,respectively.The results reveal the nonlinear diffusion behaviors of Ta_(2)NiSe_(5) in tens of picoseconds,which are attributed to the interplay between excited electrons and phonons.The trend of the measured local polarization-dependent transient reflectivity is consistent with the polarized Raman spectra results.These results show that the DMD-based pump-probe microscope is an effective and versatile tool to study the optoelectronic properties of 2D materials.

关 键 词：ANISOTROPIC MIRROR transient 

分 类 号：TH742[机械工程—光学工程] TB302[机械工程—仪器科学与技术]