Electrically Tunable Energy Bandgap in Dual-Gated Ultra-Thin Black Phosphorus Field Effect Transistors

TL;DR

This paper demonstrates that the energy bandgap of few-layer black phosphorus can be continuously and reversibly tuned using a dual-gated field-effect transistor setup, enabling potential applications in infrared optoelectronics and thermal imaging.

Contribution

We show a method to electrically tune the bandgap of few-layer black phosphorus in real time using dual-gated transistors, achieving a significant bandgap reduction.

Findings

Bandgap reduction of 124 meV observed

Bandgap tunability range from 0.10V/nm to 0.83V/nm

Potential applications in infrared optoelectronics and thermoelectric devices

Abstract

The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus (BP) by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10V/nm to 0.83V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronics, thermoelectric power generation and thermal imaging.