Electrical transport and optical properties of Cd3As2 thin films

作     者：Yun-Kun Yang Fa-Xian Xiu Feng-Qiu Wang Jun Wang Yi Shi 杨运坤;修发贤;王枫秋;王军;施毅

作者机构：Collaborative Innovation Center of Advanced MicrostructuresNanjing 210093China State Key Laboratory of Surface Physics and Department of PhysicsFudan UniversityShanghai 200433China School of Electronic Science and EngineeringNanjing UniversityNanjing 210093China School of Optoelectronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengdu 610054China State Key Laboratory of Electronic Thin Films and Integrated DevicesUniversity of Electronic Science and Technology of ChinaChengdu 610054China National Laboratory of Solid State MicrostructuresSchool of PhysicsNanjing UniversityNanjing 210093China 

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

年 卷 期：2019年第28卷第10期

页      面：93-100页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0303302 and 2018YFA0305601) the National Natural Science Foundation of China(Grant Nos.61322407,11474058,61674040,and 11874116) 

主　　题：topological Dirac semimetals thin films photodetectors ultra-fast optical switches 

摘      要：Cd3As2, as a three-dimensional(3D) topological Dirac semimetal, has attracted wide attention due to its unique physical properties originating from the 3D massless Dirac fermions. While many efforts have been devoted to the exploration of novel physical phenomena such as chiral anomaly and phase transitions by using bulk crystals, the development of high-quality and large-scale thin films becomes necessary for practical electronic and optical applications. Here, we report our recent progress in developing single-crystalline thin films with improved quality and their optical devices including Cd3As2-based heterojunctions and ultrafast optical switches. We find that a post-annealing process can significantly enhance the crystallinity of Cd3As2 in both intrinsic and Zn-doped thin films. With excellent characteristics of high mobility and linear band dispersion, Cd3As2 exhibits a good optical response in the visible-to-mid-infrared range due to an advantageous optical absorption, which is reminiscent of 3D graphene. It also behaves as an excellent saturable absorber in the mid-infrared regime. Through the delicate doping process in this material system, it may further open up the long-sought parameter space crucial for the development of compact and high-performance mid-infrared ultrafast sources.