Rectify effect of Pedot : PSS/WS₂ heterostructure

Abstract

Recently, devices based on organic and two-dimensional (2D) materials have been recognized as the easiest way to fabricate hybrid 2D van der Waals (vdW) heterojunction devices for electronic and optoelectronic applications. Depositing organic materials on 2D materials is typically demonstrated by thermal evaporation using high voltage and vacuum systems. In this paper, a simple way to fabricate organic/n-2D heterostructures, where Pedot:PSS is chosen to be the organic material due to its high conductivity, excellent film forming ability and good stability, while WS2 is selected as the n-2D material due to its well-known properties has been presented. By systematically studying the gate dependent and temperature-dependent I–V characteristics of the Pedot:PSS/WS2 heterojunctions, it is demonstrated that the device shows a diode-like behavior with rectification ratio (RF) of ≈5 and a turn on voltage of ≈2 V at room temperature (RT). Furthermore, the rectification ratio of the junction reaches up to 103 using a back-gate bias voltage (Vgs) of 20 V together with drain–source voltage (Vds) ranging from −4 to 4 V. On the basis of the results, it is demonstrated that this simple technique of fabricating organic/2D vdW heterojunctions can extend to other organics and 2D materials.