Chen Po-Han, Chen Chun-An, Lin Yu-Ting, Hsieh Ping-Yi, Chuang Meng-Hsi, Liu Xiaoze, Hsieh Tung-Ying, Shen Chang-Hong, Shieh Jia-Min, Wu Meng-Chyi, Chen Yung-Fu, Yang Chih-Chao, Lee Yi-Hsien
Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
Department of Physics, National Central University, Zhongli 32001, Taiwan.
ACS Appl Mater Interfaces. 2023 Mar 1;15(8):10812-10819. doi: 10.1021/acsami.2c19705. Epub 2023 Feb 20.
Heterogeneous integration of monolayers is an emergent route of spatially combining materials with available platforms for unprecedented properties. A long-standing challenge along this route is to manipulate interfacial configurations of each unit in stacking architecture. A monolayer of transition metal dichalcogenides (TMDs) offers an embodiment of studying interface engineering of integrated systems because optoelectronic performances generally trade off with each other due to interfacial trap states. While ultrahigh photoresponsivity of TMDs phototransistors has been realized, a long response time commonly appears and hinders applications. Here, fundamental processes in excitation and relaxation of the photoresponse are studied and correlated with interfacial traps of the monolayer MoS. A mechanism for the onset of saturation photocurrent and the reset behavior in the monolayer photodetector is illustrated based on device performances. Electrostatic passivation of interfacial traps is achieved with the bipolar gate pulse and significantly reduces the response time for photocurrent to reach saturated states. This work paves the way toward fast-speed and ultrahigh-gain devices of stacked two-dimensional monolayers.
单层的异质集成是一种将材料与现有平台进行空间组合以获得前所未有的特性的新兴途径。沿着这条途径长期存在的一个挑战是在堆叠结构中操纵每个单元的界面构型。单层过渡金属二硫属化物（TMDs）为研究集成系统的界面工程提供了一个实例，因为由于界面陷阱态，光电性能通常会相互权衡。虽然已经实现了TMDs光晶体管的超高光响应性，但通常会出现较长的响应时间并阻碍其应用。在此，研究了光响应激发和弛豫的基本过程，并将其与单层MoS的界面陷阱相关联。基于器件性能，阐述了单层光电探测器中饱和光电流起始和复位行为的机制。通过双极栅极脉冲实现了界面陷阱的静电钝化，并显著缩短了光电流达到饱和状态的响应时间。这项工作为堆叠二维单层的高速和超高增益器件铺平了道路。
