MoS_(2)/MoTe_(2)垂直异质结的电荷传输及其调制  

Charge transmission of MoS_(2)/MoTe_(2) vertical heterojunction and its modulation

作　　者：温恒迪 刘跃 甄良[1,2,3] 李洋 徐成彦 Wen Heng-Di;Liu Yue;Zhen Liang;Li Yang;Xu Cheng-Yan(School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China;Sauvage Laboratory for Smart Materials,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China;MOE Key Laboratory of Micro-Systems and Micro-Structures Manufacturing,Harbin Institute of Technology,Harbin 150080,China)

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001 [2]哈尔滨工业大学(深圳),索维奇智能新材料实验室(诺贝尔奖科学家实验室),深圳518055 [3]哈尔滨工业大学,微系统与微结构制造教育部重点实验室,哈尔滨150080

出　　处：《物理学报》2023年第3期199-206,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51772064,51902069);黑龙江省自然科学基金(批准号:YQ2021E019);深圳市科学技术项目(批准号:RCJC20210706091950025)资助的课题。

摘　　要：二维材料异质结器件具有纳米级厚度及范德瓦耳斯接触表面,因而表现出独特的光电特性.本文构建了栅压可调的MoS_(2)/MoTe_(2)垂直异质结器件,利用开尔文探针力显微镜(KPFM)技术结合电输运测量,揭示了MoS_(2)/MoTe_(2)异质结分别在黑暗和532 nm激光照射条件下的电荷输运行为,发现随着栅压的变化异质结表现出从n-n^(+)结到p-n结的反双极性特征.系统地解释了MoS_(2)/MoTe_(2)异质结的电荷输运机制,包括n-n^(+)结和p-n结在正偏和反偏下条件下的电荷输运过程、随栅压变化而发生的转变的结区行为、接触势垒对电荷输运的影响、n-n^(+)结和p-n结具有不同整流特征的原因、偏压对带间隧穿的重要作用及光生载流子对电学输运行为的影响等.本文所使用的方法可推广到其他二维异质结体系,为提高二维半导体器件性能及其应用提供了重要的参考和借鉴.The heterojunction device based on two-dimensional materials possesses unique photoelectric properties due to its nanoscale thickness and van der Waals(vdWs)contact surface.In this paper,a gate-volt age-tunable MoS_(2)/MoTe_(2)vertical vdWs heterojunction device is constructed.The Kelvin probe force microscopy(KPFM)technology is combined with the electric transport measurement technology,thereby revealing the charge transport behavior of the MOS_(2)/MoTe_(2)heterojunction under dark condition and laser-irradition condition,including the bipolarity characteristics of the transition from n-n^(+)junction to p-n junction.In this paper,the charge transport mechanism of heterojunction is explained comprehensively and systematically,including the charge transmission process of n-n^(+)junction and p-n junction under positive and negative bias conditions,the transformation of nodule behavior with gate voltage,the influence of barriers on charge transmission,the different rectification characteristics between n-n^(+)junction and p-n junction,the major role of source and leakage bias voltage in band tunneling,and the influence of photogenerated carriers on electrical transmission.The method in this work can be generalized to other two-dimensional heterojunction systems and also provide an important reference for improving the performance of two-dimensional semiconductor devices and their applications in the future.

关 键 词：二维过渡金属硫族化合物异质结 电荷传输机制 能带结构 开尔文探针力显微镜 

分 类 号：O469[理学—凝聚态物理]