State Key Laboratory of ASIC (Application-Specific Integrated Circuit) System, School of Microelectronics, Fudan University, Shanghai, China.
Sci Adv. 2017 May 19;3(5):e1602246. doi: 10.1126/sciadv.1602246. eCollection 2017 May.
Transistors with exfoliated two-dimensional (2D) materials on a SiO/Si substrate have been applied and have been proven effective in a wide range of applications, such as circuits, memory, photodetectors, gas sensors, optical modulators, valleytronics, and spintronics. However, these devices usually suffer from limited gate control because of the thick SiO gate dielectric and the lack of reliable transfer method. We introduce a new back-gate transistor scheme fabricated on a novel AlO/ITO (indium tin oxide)/SiO/Si "stack" substrate, which was engineered with distinguishable optical identification of exfoliated 2D materials. High-quality exfoliated 2D materials could be easily obtained and recognized on this stack. Two typical 2D materials, MoS and ReS, were implemented to demonstrate the enhancement of gate controllability. Both transistors show excellent electrical characteristics, including steep subthreshold swing (62 mV dec for MoS and 83 mV dec for ReS), high mobility (61.79 cm V s for MoS and 7.32 cm V s for ReS), large on/off ratio (~10), and reasonable working gate bias (below 3 V). Moreover, MoS and ReS photodetectors fabricated on the basis of the scheme have impressively leading photoresponsivities of 4000 and 760 A W in the depletion area, respectively, and both have exceeded 10 A W in the accumulation area, which is the best ever obtained. This opens up a suite of applications of this novel platform in 2D materials research with increasing needs of enhanced gate control.
在 SiO/Si 衬底上具有剥离二维（2D）材料的晶体管已经得到了应用，并已在各种应用中得到了验证，例如电路、存储器、光电探测器、气体传感器、光调制器、谷电子学和自旋电子学。然而，由于厚的 SiO 栅介质和缺乏可靠的转移方法，这些器件通常受到有限的栅极控制。我们引入了一种新的背栅晶体管方案，该方案在新型 AlO/ITO（氧化铟锡）/SiO/Si“堆叠”衬底上制造，该衬底采用了可区分剥离 2D 材料的光学识别技术。在这个堆叠体上，可以轻松获得和识别高质量的剥离 2D 材料。两种典型的 2D 材料，MoS 和 ReS，被实施以证明栅极可控性的增强。两种晶体管都表现出优异的电学特性，包括陡峭的亚阈值摆幅（MoS 为 62 mV dec，ReS 为 83 mV dec）、高迁移率（MoS 为 61.79 cm V s，ReS 为 7.32 cm V s）、大的导通/关断比（~10）和合理的工作栅极偏压（低于 3 V）。此外，基于该方案制造的 MoS 和 ReS 光电探测器在耗尽区的光响应率分别达到了 4000 和 760 A W，在积累区的光响应率均超过了 10 A W，这是迄今为止最好的结果。这为在 2D 材料研究中使用这种新型平台提供了一系列应用，这些应用需要增强栅极控制。
