Gate Tunable Quantum Oscillations in Air-Stable and High Mobility Few-Layer Phosphorene Heterostructures

TL;DR

This study demonstrates gate-tunable quantum oscillations in air-stable, high-mobility few-layer phosphorene heterostructures, revealing their potential for 2D physics and electronic applications.

Contribution

We fabricated stable phosphorene-hBN heterostructures with edge contacts, observing gate-tunable quantum oscillations and detailed electronic properties.

Findings

Mobility up to 4000 cm²/Vs in ambient conditions

Observation of gate-tunable SdH oscillations and Zeeman splitting

Cyclotron mass increases as Fermi level approaches valence band edge

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 (1D) edge contacts. These transistors are stable in ambient conditions for >300 hours, and display ambipolar behavior, a gate-dependent metal-insulator transition, and mobility up to 4000 $cm^2$/Vs. At low temperatures, we observe gate-tunable Shubnikov de Haas (SdH) magneto-oscillations and Zeeman splitting in magnetic field with an estimated g-factor ~2. The cyclotron mass of few-layer phosphorene holes is determined to increase from 0.25 to 0.31 $m_e$ as the Fermi level moves towards the valence band edge. Our results underscore the potential of few-layer phosphorene (FLP) as both a platform for novel 2D physics and an electronic material for semiconductor applications.