Realizing Large-Scale, Electronic-Grade Two-Dimensional Semiconductors

Yu-Chuan Lin; Bhakti Jariwala; Brian M Bersch; Ke Xu; Yifan Nie; Baoming Wang; Sarah M Eichfeld; Xiaotian Zhang; Tanushree H Choudhury; Yi Pan; Rafik Addou; Christopher M Smyth; Jun Li; Kehao Zhang; M Aman Haque; Stefan Fölsch; Randall M Feenstra; Robert M Wallace; Kyeongjae Cho; Susan K Fullerton-Shirey; Joan M Redwing; Joshua A Robinson

doi:10.1021/acsnano.7b07059

Realizing Large-Scale, Electronic-Grade Two-Dimensional Semiconductors

ACS Nano. 2018 Feb 27;12(2):965-975. doi: 10.1021/acsnano.7b07059. Epub 2018 Jan 23.

Authors

Yu-Chuan Lin¹, Bhakti Jariwala¹, Brian M Bersch¹, Ke Xu², Yifan Nie³, Baoming Wang⁴, Sarah M Eichfeld¹, Xiaotian Zhang¹, Tanushree H Choudhury⁵, Yi Pan⁶, Rafik Addou³, Christopher M Smyth³, Jun Li⁷, Kehao Zhang¹, M Aman Haque⁴, Stefan Fölsch⁶, Randall M Feenstra⁷, Robert M Wallace³, Kyeongjae Cho³, Susan K Fullerton-Shirey^{2

8}, Joan M Redwing^{1

5}, Joshua A Robinson^{1

5}

Affiliations

¹ Department of Materials Science and Engineering, Materials Research Institute, and Center for 2D and Layered Materials (2DLM), The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
² Department of Chemical and Petroleum Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15213, United States.
³ Department of Materials Science and Engineering, The University of Texas at Dallas , Richardson, Texas 75080, United States.
⁴ Department of Mechanical Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
⁵ Two-Dimensional Crystal Consortium (2DCC), The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
⁶ Paul-Drude-Institut für Festkörperelektronik , Hausvogteiplatz 5-7, Berlin 10117, Germany.
⁷ Department of Physics, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
⁸ Department of Electrical and Computer Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15213, United States.

PMID: 29360349
DOI: 10.1021/acsnano.7b07059

Abstract

Atomically thin transition metal dichalcogenides (TMDs) are of interest for next-generation electronics and optoelectronics. Here, we demonstrate device-ready synthetic tungsten diselenide (WSe₂) via metal-organic chemical vapor deposition and provide key insights into the phenomena that control the properties of large-area, epitaxial TMDs. When epitaxy is achieved, the sapphire surface reconstructs, leading to strong 2D/3D (i.e., TMD/substrate) interactions that impact carrier transport. Furthermore, we demonstrate that substrate step edges are a major source of carrier doping and scattering. Even with 2D/3D coupling, transistors utilizing transfer-free epitaxial WSe₂/sapphire exhibit ambipolar behavior with excellent on/off ratios (∼10⁷), high current density (1-10 μA·μm^-1), and good field-effect transistor mobility (∼30 cm²·V^-1·s^-1) at room temperature. This work establishes that realization of electronic-grade epitaxial TMDs must consider the impact of the TMD precursors, substrate, and the 2D/3D interface as leading factors in electronic performance.

Keywords: field-effect transistors; metal−organic chemical vapor deposition (MOCVD); transition metal dichalcogenides; tungsten diselenide (WSe2); two-dimensional materials; van der Waals epitaxy.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.