High mobility flexible graphene field-effect transistors and ambipolar radio-frequency circuits

Field-effect transistors (GFETs) were fabricated on mechanically flexible substrates using chemical vapor deposition grown graphene. High current density (nearly 200 mu A mu m(-1)) with saturation, almost perfect ambipolar electron-hole behavior, high transconductance (120 mu S mu m(-1)) and good stability over 381 days were obtained. The average carrier mobility for holes (electrons) is 13 540 cm(2) V-1 s(-1) (12 300 cm(2) V-1 s(-1)) with the highest value over 24 000 cm(2) V-1 s(-1) (20 000 cm(2) V-1 s(-1)) obtained in flexible GFETs. Ambipolar radio-frequency circuits, frequency doubler, were constructed based on the high performed flexible GFET, which show record high output power spectra purity (similar to 97%) and high conversion gain of -13.6 dB. Bending measurements show the flexible GFETs are able to work under modest strain. These results show that flexible GFETs are a very promising option for future flexible radio-frequency electronics.