Gate voltage control of helicity-dependent photocurrent and polarization detection in(Bi_(1-x)Sb_(x))_(2)Te_(3)topological insulator thin films  

作　　者：SHENZHONG CHEN JINLING YU XIYU HONG KEJING ZHU YONGHAI CHEN SHUYING CHENG YUNFENG LAI KE HE QIKUN XUE 

机构地区：[1]Institute of Micro/Nano Devices and Solar Cells,School of Physics and Information Engineering,Fuzhou University,Fuzhou 350108,China [2]State Key Laboratory of Low-Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing 100084,China [3]Key Laboratory of Semiconductor Materials Science,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China [4]College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Photonics Research》2023年第11期1902-1911,共10页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(62074036,61674038,11574302);Foreign Cooperation Project of Fujian Province(2023I0005);Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics(KF202108);National Key Research and Development Program of China(2016YFB0402303);Foundation of Fujian Provincial Department of Industry and Information Technology(82318075)。

摘　　要：Optical helicity provides us with an effective means to control the helicity-dependent photocurrent in the spinmomentum-locked surface states of topological insulators(TIs).Also,the TIs show potential in polarization detection as an intrinsic solid-state optical chirality detector for easier integration and fabrication.However,the complex photoresponses with the circular photogalvanic effect,the linear photogalvanic effect,and the photon drag effect in the TIs prevent them from direct chirality detection of the elliptically polarized light.Here,by fitting with the theoretical models to the measured photocurrents,the microscopic origin of different components of the helicity-dependent photocurrent has been demonstrated.We show a comprehensive study of the helicitydependent photocurrent in(Bi_(1-x)Sb_(x))_(2)Te_(3)thin films of different thicknesses as a function of the light incident angle and the gate-tuned chemical potential.The observation of the light incident angle dependence of the helicitydependent photocurrent provides us with a polarization detection strategy using a TI thin film without the use of any additional optical elements,and the detection accuracy can be enhanced by gate tuning.Additionally,the Stokes parameters can be extracted by arithmetic operation of photocurrents measured with different incident angles and gating voltages for complete characterization of the polarization states of a light beam.Using this means,we realize the polarization detection and the Stokes parameters analysis with a single device.Our work provides an alternative solution to develop miniaturized intrinsic polarization-sensitive photodetectors.

关 键 词：TOPOLOGICAL INCIDENT INSULATOR 

分 类 号：O43[机械工程—光学工程]