Report

All-printed thin-film transistors from networks of liquid-exfoliated nanosheets

See allHide authors and affiliations

Science  07 Apr 2017:
Vol. 356, Issue 6333, pp. 69-73
DOI: 10.1126/science.aal4062

You are currently viewing the abstract.

View Full Text

Printing nanosheet-network transistors

Two-dimensional (2D) materials such as graphene and metal chalcogenides such as tungsten diselenide (WSe2) are attractive for use in low-cost thin-film transistors (TFTs) because they have high charge-carrier mobility. Kelly et al. printed TFTs from networks of exfoliated dispersions of 2D materials with graphene contacts, WSe2 as the semiconductor, and a boron nitride separator. Electrolytic gating with ionic liquids enabled higher operating currents than achieved with comparable organic TFTs.

Science, this issue p. 69

Abstract

All-printed transistors consisting of interconnected networks of various types of two-dimensional nanosheets are an important goal in nanoscience. Using electrolytic gating, we demonstrate all-printed, vertically stacked transistors with graphene source, drain, and gate electrodes, a transition metal dichalcogenide channel, and a boron nitride (BN) separator, all formed from nanosheet networks. The BN network contains an ionic liquid within its porous interior that allows electrolytic gating in a solid-like structure. Nanosheet network channels display on:off ratios of up to 600, transconductances exceeding 5 millisiemens, and mobilities of >0.1 square centimeters per volt per second. Unusually, the on-currents scaled with network thickness and volumetric capacitance. In contrast to other devices with comparable mobility, large capacitances, while hindering switching speeds, allow these devices to carry higher currents at relatively low drive voltages.

View Full Text