Tunable 2H–TaSe_2 room-temperature terahertz photodetector

作     者：Jin Wang Cheng Guo Wanlong Guo Lin Wang Wangzhou Shi Xiaoshuang Chen 王瑾;郭程;郭万龙;王林;石旺舟;陈效双

作者机构：Department of Physics Shanghai Normal University State Key Laboratory for Infrared Physics Shanghai Institute of Technical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2019年第28卷第4期

页      面：18-22页

核心收录：

学科分类：0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0803[工学-光学工程] 

基　　金：Project supported by the State Key Basic Research Program of China(Grant Nos.2017YFA0205801,2017YFA0305500,and 2013CB632705) the National Natural Science Foundation of China(Grant Nos.11334008,61290301,61521005,61405230,and 61675222) the Youth Innovation Promotion Association(CAS) the Aviation Science Fund(Grant No.20162490001) 

主　　题：terahertz detection transition metal dichalcogenides photoconductive 

摘      要：Two-dimensional transition metal dichalcogenides(TMDs) provide fertile ground to study the interplay between dimensionality and electronic properties because they exhibit a variety of electronic phases, such as semiconducting, superconducting, charge density waves(CDW) states, and other unconventional physical properties. Compared with other classical TMDs, such as Mott insulator 1T–TaS_2 or superconducting 2H–NbSe_2, bulk 2H–TaSe_2 has been a canonical system and a touchstone for modeling the CDW measurement with a less complex phase diagram. In contrast to ordinary semiconductors that have only single-particle excitations, CDW can have collective excitation and carry current in a collective fashion. However, manipulating this collective condensation of these intriguing systems for device applications has not been explored. Here, the CDW-induced collective driven of non-equilibrium carriers in a field-effect transistor has been demonstrated for the sensitive photodetection at the highly-pursuit terahertz band. We show that the 2H–TaSe_2-based photodetector exhibits a fast photoresponse, as short as 14 μs, and a responsivity of over 27 V/W at room temperature. The fast response time, relative high responsivity and ease of fabrication of these devices yields a new prospect of exploring CDW condensate in TMDs with the aim of overcoming the existing limitations for a variety of practical applications at THz spectral range.