Flexible p-Type WSe2 Transistors with Alumina Top-Gate Dielectric.

Abstract

Tungsten diselenide (WSe2) field-effect transistors (FETs) are promising for emerging electronics because of their tunable polarity, enabling complementary transistor technology, and their suitability for flexible electronics through material transfer. In this work, we demonstrate flexible p-type WSe2 FETs with absolute drain currents |ID| up to 7 μA/μm. We achieve this by fabricating flexible top-gated FETs with a combined WSe2 and metal contact transfer approach using WSe2 grown by metal-organic chemical vapor deposition on sapphire. Despite moderate WSe2 crystal grain size, our devices show similar or higher |ID| and ID on/off ratio (∼105) compared to most devices with exfoliated single-crystal WSe2 from the literature. We analyze charge trapping in our devices using pulsed and bias stress measurements. Notably, the high |ID| values are preserved during pulsing, where charge trapping is minimized. Overall, we demonstrate a fabrication approach advantageous for high drain currents in flexible 2D transistors.