Towards High-Performance Two-Dimensional Black Phosphorus Optoelectronic Devices: the Role of Metal Contacts

TL;DR

This paper investigates how metal contacts influence the performance of black phosphorus optoelectronic devices, demonstrating record high photoresponsivity through contact engineering and analyzing the effects of metal work functions.

Contribution

It provides new insights into contact engineering for black phosphorus devices, showing how metal work functions affect device behavior and achieving record photoresponsivity.

Findings

Higher work function metals increase hole currents in p-type transistors.

Lower work function metals induce ambipolar behavior.

Record high photoresponsivity (223 mA/W) achieved in black phosphorus photodetectors.

Abstract

The metal contacts on 2D black phosphorus field-effect transistor and photodetectors are studied. The metal work functions can significantly impact the Schottky barrier at the metal-semiconductor contact in black phosphorus devices. Higher metal work functions lead to larger output hole currents in p-type transistors, while ambipolar characteristics can be observed with lower work function metals. Photodetectors with record high photoresponsivity (223 mA/W) are demonstrated on black phosphorus through contact-engineering.