Intrinsic and extrinsic electrical and thermal transport of bulk black phosphorus

Abstract

We report a comprehensive investigation of the electrical, thermal, and thermoelectric transport properties of bulk single-crystalline black phosphorus in wide temperature (2--300 K) and field (0--9 T) ranges. Electrical transport below $T\ensuremath{\approx}$ 250 K is found to be dominated by extrinsic hole-type charge carriers with large mobility exceeding ${10}^{4}$ ${\mathrm{cm}}^{2}$/V s at low temperatures. While thermal transport measurements reveal an enhanced in-plane thermal conductivity maximum $\ensuremath{\kappa}$ = 180 W/m K at $T\ensuremath{\approx}$ 25 K, it appears still to be largely constrained by extrinsic phonon scattering processes, e.g., the electron-phonon process, in addition to intrinsic umklapp scattering. The thermoelectric power and Nernst effect seem to be strongly influenced by ambipolar transport of charge carriers with opposite signs in at least the high-temperature region above 200 K, which diminishes the thermoelectric power factor of this material. Our results provide a timely update to the transport properties of bulk black phosphorus for future fundamental and applied research.