Field-effect transistors of high-mobility few-layer SnSe2
Abstract
We report the transport properties of mechanically exfoliated few-layer SnSe2 flakes, whose mobility is found with four probe measurements to be 85 cm2V-1s-1 at 300 K, higher than those of the majority of few-layer transitional metal dichalcogenides (TMDs). The mobility increases strongly with decreased temperature, indicating a phonon limited transport. The conductivity of the semiconducting SnSe2 shows a metallic behavior, which is explained by two competing factors involving the different temperature dependence of mobility and carrier density. The Fermi level is found to be 87 meV below the conduction band minima (CBM) at 300 K and 12 meV below the CBM at 78 K, resulting from a heavy n-type doping. Previous studies have found SnSe2 field-effect transistors (FETs) to be very difficult to turn off. We find the limiting factor to be the flake thickness compared with the maximum depletion width. With fully depleted devices, we are able to achieve a current on-off ratio of 105. These results demonstrate the great potential of SnSe2 as a two dimensional (2D) semiconducting material.
National Natural Science Foundation of China (Grant No. 11504234), Science and Technology Commission of Shanghai Municipality (Grant Nos. 15QA1403200 and 14PJ1406600), the Strategic Priority Research Program (B) of the CAS (Grant No. XDB04030000).- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2017
- Bibcode:
- 2017APS..MAR.V1007G