Ultrafast, highly-sensitive infrared photodetectors based on two-dimensional oxyselenide crystals

TL;DR

This paper introduces a 2D Bi2O2Se-based infrared photodetector that combines ultrafast response, high sensitivity, and stability, advancing the capabilities of 2D material-based infrared sensing technologies.

Contribution

The study presents a novel 2D oxyselenide crystal-based infrared photodetector with superior speed and sensitivity, outperforming existing 2D materials in multiple key performance metrics.

Findings

High sensitivity of ~65 A/W at 1200 nm

Ultrafast photoresponse of ~1 ps at room temperature

Excellent stability and flexibility of the detector

Abstract

Infrared detection and sensing is deeply embedded in modern technology and human society and its development has always been benefitting from the discovery of new photoelectric response materials. The rise of two-dimensional (2D) materials, thanks to their distinct electronic structure, extreme dimensional confinement and strong light-matter interactions, provides new material platform for next-generation infrared photodetection. Ideal infrared detectors should have fast respond, high sensitivity and air-stability, which is rare to meet at the same time for all existing 2D materials, either graphene, transition metal dichalcogenide or black phosphorous. Herein we demonstrate a new infrared photodetector based on 2D Bi2O2Se crystals, whose main characteristics are superb in the whole 2D family: high sensitivity of ~65 A/W at 1200 nm and ultrafast intrinsic photoresponse of ~1 ps at room temperature. Such great performance is attributed to the suitable electronic bandgap and high carrier mobility of 2D oxyselenide. With additional merits of mass production, excellent stability and flexibility, 2D oxyselenide detectors should open new avenues in highly-sensitive, high-speed, low-cost, flexible infrared photodetection and imaging.