Gate tunable quantum oscillations in air-stable and high mobility few-layer phosphorene heterostructures

Abstract

As the only non-carbon elemental layered allotrope, few-layer black phosphorus or phosphorene has emerged as a novel two-dimensional (2D) semiconductor with both high bulk mobility and a band gap. Here we report fabrication and transport measurements of phosphorene-hexagonal BN (hBN) heterostructures with one-dimensional edge contacts. These transistors are stable in ambient conditions for >300 h, and display ambipolar behavior, a gate-dependent metal–insulator transition, and mobility up to 4000 cm2 V−1 s−1. At low temperatures, we observe gate-tunable Shubnikov de Haas magneto-oscillations and Zeeman splitting in magnetic field with an estimated g-factor ∼2. The cyclotron mass of few-layer phosphorene (FLP) holes is determined to increase from 0.25 to 0.31 me as the Fermi level moves towards the valence band edge. Our results underscore the potential of FLP as both a platform for novel 2D physics and an electronic material for semiconductor applications.