▎ 摘　　要

Flexible graphene field-effect transistors (GFETs) are fabricated with graphene channels fully encapsulated in hexagonal boron nitride (hBN) implementing a self-aligned fabrication scheme. Flexible GFETs fabricated with channel lengths of 2 gm demonstrate exceptional room-temperature carrier mobility (mu(FE) = 10 000 cm(2) V-1 s(-1)), strong current saturation characteristics (peak output resistance, r(0) = 2000 Omega), and high mechanical flexibility (strain limits of 1%). These values of mu(FE) and r(0) are unprecedented in flexible GFETs. Flexible radio frequency FETs (RF-FETs) with channel lengths of 375 nm demonstrate mu(FE) = 2200 cm(2) V-1 s(-1) and r(0) = 132.5 Omega. Unity-current gain frequencies, f(T), and unity-power gain frequencies, f(max), reach 12.0 and 10.6 GHz, respectively. The corresponding ratio of cutoff frequencies approaches unity (f(max)/f(T) = 0.9), a record value for flexible GFETs. Intrinsic f(T) and f(max) are 29.7 and 15.7 GHz, respectively. The outstanding electronic characteristics are attributed to the improved dielectric environment provided by full hBN encapsulation of the graphene channel in conjunction with an optimized, self-aligned device structure. These results establish hBN as a mechanically robust dielectric that can yield enhanced electronic characteristics to a diverse array of graphene-based flexible electronics.