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

Tungsten diselenide (WSe) 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 WSe FETs with absolute drain currents || up to 7 μA/μm. We achieve this by fabricating flexible top-gated FETs with a combined WSe and metal contact transfer approach using WSe grown by metal-organic chemical vapor deposition on sapphire. Despite moderate WSe crystal grain size, our devices show similar or higher || and on/off ratio (∼10) compared to most devices with exfoliated single-crystal WSe from the literature. We analyze charge trapping in our devices using pulsed and bias stress measurements. Notably, the high || 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.