Suppressing Ambipolar Characteristics of WSe2 Field Effect Transistors Using Graphene Oxide

Abstract

Monolayer (1L) tungsten diselenide (WSe2) is of interest for next generation ultrathin flexible electronic devices. However, typical WSe2 field effect transistors (FETs) show ambipolar characteristics that are not desirable for complementary field-effect-transistors and circuits. Here, significant suppression of the ambipolar characteristics of a 1L-WSe2 FET is demonstrated by using an electron withdrawing functional group of graphene oxide (GO). The pristine 1L-WSe2 FET shows n-type dominant ambipolar characteristics, whereas the GO coated 1L-WSe2 FET shows unipolar p-type behavior with a huge decrease (1/10(6)) of current level of the n-channel. Also, the current level of the p-channel increases up to ten times that of the pristine 1L-WSe2 FET. These results are applicable for the realization of flexible nanoscale digital logic devices by using transition metal dichalcogenides.