Graphene-like two-dimensional (2D) materials, not only are interesting for their exotic electronic structure and fundamental electronic transport or optical properties but also, hold promises for device miniaturization down to atomic thickness. As one material belonging to this category, InSe is not only a promising candidate for optoelectronic devices but also has potential for ultrathin field effect transistor (FET) with high mobility transport. In this work, various substrates such as PMMA, bare silicon oxide, passivated silicon oxide, and silicon nitride were used to fabricate multi-layer InSe FET devices. Through back gating and Hall measurement in four-probe configuration, the devices' field effect mobility and intrinsic Hall mobility were extracted at various temperatures to study the material's intrinsic transport behavior and the effect of dielectric substrate. The sample's field effect and Hall mobilities over the range of 77-300K fall in the range of 0.1-2.0$\times$10$^3$ cm$^2$/Vs, which are comparable or better than the state of the art FETs made of 2D transition metal-dichalcogenides.
Screening limited switching performance of multilayer 2D semiconductor FETs: the case for SnS
制作了厚度在50 ~ 100 nm之间的p型多层锡硫化物（SnS）场效应晶体管（FET）器件，并对其性能进行了研究。该器件显示出各向异性的面内电导和室温场效应迁移率~5 - 10 cm $^2$ /Vs。然而，该器件在室温下显示出可观的关断态电导和~10的开-关比。SnS器件在耗尽区的弱栅极调谐行为是由有限载流子屏蔽长度效应引起的，该效应导致SnS中本征缺陷诱导的空穴形成导电表面层。通过刻蚀和Cs2 CO 3的n型表面掺杂来减少/补偿SnS片顶面附近的不可选通的空穴，器件的通断比和空穴霍尔迁移率都得到了一个数量级的提高，室温下的霍尔迁移率约为100 cm $^2$ /Vs。这项工作表明，为了获得有效的开关和低关断状态功耗，二维（2D）的半导体为基础的耗尽型场效应晶体管应限制其厚度内的德拜屏蔽长度的半导体中的载流子。
Maximizing the spin-orbit torque efficiency of Pt/Ti multilayers by optimization of the tradeoff between the intrinsic spin Hall conductivity and carrier lifetime
Enhancement of Perpendicular Magnetic Anisotropy and Transmission of Spin-Hall-Effect-Induced Spin Currents by a Hf Spacer Layer in W/Hf/CoFeB/MgO Layer
