Ambipolar phosphorene field-effect transistors with dielectric capping

摘要

Phosphorene, the two-dimensional form of black phosphorus, has been given much attention very recently. [1-3] It obtains a layer-dependent tunable direct band gap from 0.3 eV up to 1.55 eV and has a potential for next generation electronic and optoelectronic applications.[1,4] In this study, we fabricate few-layer phosphorene field-effect transistors and achieve a high on-current of 144 mA/mm and hole mobility up to 95.6 cm2/V·s. We further investigate the dielectric integration on phosphorene transistors and observe a transition from p-type to ambipolar behavior. The changes in effective Schottky barrier heights for electrons/holes at metal contacts after dielectric growth are attributed to the transition observed.