Ambipolar Black Phosphorus MOSFETs With Record n-Channel Transconductance

Ambipolar black phosphorus MOSFETs with record n-channel extrinsic transconductance are reported. The devices consist of multilayer black phosphorus aligned to a local back-gate electrode with 10-nm-thick HfO2 gate dielectric. Before passivation, devices with 0.3-mu m gate length behaved as p-MOSFETs with peak extrinsic transconductance, gm, of 282 mu S/mu m at V-DS = -2 V. After passivation, the same devices displayed the ambipolar behavior, and when tested as n-MOSFETs, had peak g(m) = 66 mu S/mu m at V-DS = +2 V, and similar devices on the same wafer had gm as high as 80 mu S/mu m. These results are an important step toward the realization of high-performance black phosphorus complementary logic circuits.