Ambipolar transport in van der Waals black arsenic field effect transistors
Prafful Golani, Hwanhui Yun, Supriya Ghosh, Jiaxuan Wen, K. Andre Mkhoyan, Steven J. Koester
Abstract
Abstract Black arsenic (BAs) is an elemental van der Waals semiconductor that is promising for a wide range of electronic and photonic applications. The narrow bandgap and symmetric band structure suggest that ambipolar (both n - and p -type) transport should be observable, however, only p -type transport has been experimentally studied to date. Here, we demonstrate and characterize ambipolar transport in exfoliated BAs field effect transistors. In the thickest flakes (∼ 80 nm), maximum currents, I max , up to 60 μ A μ m −1 and 90 μ A μ m −1 are achieved for hole and electron conduction, respectively. Room-temperature hole (electron) mobilities up to 150 cm 2 V −1 s −1 (175 cm 2 V −1 s −1 ) were obtained, with temperature-dependence consistent with a phonon-scattering mechanism. The Schottky barrier height for Ni contacts to BAs was also extracted from the temperature-dependent measurements. I max for both n - and p -type conductivity was found to decrease with reduced thickness, while the ratio of I max to the minimum current, I min , increased. In the thinnest flakes (∼ 1.5 nm), only p -type conductivity was observed with the lowest value of I min = 400 fA μ m −1 . I max / I min ratios as high as 5 × 10 5 (5 × 10 2 ) were obtained, for p - ( n- channel) devices. Finally, the ambipolarity was used to demonstrate a complementary logic inverter and a frequency doubling circuit.