Siao Ming-Deng, Lin Yung-Chang, He Tao, Tsai Meng-Yu, Lee Kuei-Yi, Chang Shou-Yi, Lin Kuang-I, Lin Yen-Fu, Chou Mei-Yin, Suenaga Kazu, Chiu Po-Wen
Department of Electrical Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan.
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8565, Japan.
Small. 2021 Apr;17(17):e2007171. doi: 10.1002/smll.202007171. Epub 2021 Mar 12.
Band structure by design in 2D layered semiconductors is highly desirable, with the goal to acquire the electronic properties of interest through the engineering of chemical composition, structure, defect, stacking, or doping. For atomically thin transition metal dichalcogenides, substitutional doping with more than one single type of transition metals is the task for which no feasible approach is proposed. Here, the growth of WS monolayer is shown codoped with multiple kinds of transition metal impurities via chemical vapor deposition controlled in a diffusion-limited mode. Multielement embedment of Cr, Fe, Nb, and Mo into the host lattice is exemplified. Abundant impurity states thus generate in the bandgap of the resultant WS and provide a robust switch of charging/discharging states upon sweep of an electric filed. A profound memory window exists in the transfer curves of doped WS field-effect transistors, forming the basis of binary states for robust nonvolatile memory. The doping technique presented in this work brings one step closer to the rational design of 2D semiconductors with desired electronic properties.
通过设计二维层状半导体的能带结构是非常可取的，目标是通过化学成分、结构、缺陷、堆叠或掺杂工程来获得感兴趣的电子特性。对于原子级薄的过渡金属二硫属化物，用不止一种单一类型的过渡金属进行替代掺杂是一项尚未提出可行方法的任务。在此，展示了通过在扩散限制模式下控制化学气相沉积，生长共掺杂多种过渡金属杂质的WS单层。举例说明了Cr、Fe、Nb和Mo在主体晶格中的多元素嵌入。由此在所得WS的带隙中产生了丰富的杂质态，并在电场扫描时提供了充电/放电状态的稳健切换。在掺杂的WS场效应晶体管的转移曲线中存在一个深刻的记忆窗口，形成了用于稳健非易失性存储器的二进制状态的基础。这项工作中提出的掺杂技术使具有所需电子特性的二维半导体的合理设计又迈进了一步。
