Few-layer SnSe2 transistors with high on/off ratios

We report few-layer SnSe2 field effect transistors (FETs) with high current on/off ratios. By trying different gate configurations, 300 nm SiO2 and 70 nm HfO2 as back gate only and 70 nm HfO2 as back gate combined with a top capping layer of polymer electrolyte, few-layer SnSe2 FET with a current on/off ratio of 104 can be obtained. This provides a reliable solution for electrically modulating quasi-two-dimensional materials with high electron density (over 1013 cm−2) for field-effect transistor applications.