Amalgamated organic polymer of PVA/P(VDF-TrFE) as back gate dielectric in WS2 FET fabrication

Abstract

2D WS₂ channel combined with organic polymer dielectrics have garnered significant attention due to their promising applications in FETs, owing to their exceptional mechanical flexibility and cost-effective fabrication process. WS₂ FETs with polymer dielectrics not only surpass the thermal constraints but also enable low-voltage operation, providing a notable advantage over traditional devices. Conventional SiO₂ dielectrics often suffer from high oxide trap density, which adversely affects device performance. To address these issues, this study proposes the incorporation of a stack of low-k and high-k organic polymer dielectrics in WS₂-FET fabrication, enabling low-voltage operation at room temperature. Polymer gate dielectrics have demonstrated a remarkable ability to enhance the efficiency of 2D WS₂-FETs, contributing to the development of versatile and energy-efficient device architectures. This work demonstrates the fabrication and electrical characterization of WS₂-FETs using a PVA/P(VDF-TrFE) organic polymer dielectric stack. The findings reveal that the few-layer WS₂-FET structures exhibit a field-effect mobility (μ_FE) of ∼215.2 cm²/Vs and I_ON/I_OFF current ratio of around ∼10⁷.