# Palladium Diselenide Long-Wavelength Infrared Photodetector with High Sensitivity and Stability

## TL;DR

This paper presents a room-temperature, highly sensitive, and stable long-wavelength infrared photodetector based on PdSe2, achieving record-high responsivity and low noise, advancing 2D material-based IR detection technology.

## Contribution

The study introduces a PdSe2-based heterostructure photodetector with unprecedented responsivity and stability for long-wavelength IR detection at room temperature.

## Key findings

- Achieved ~42.1 AW-1 responsivity at 10.6 μm.
- Suppressed dark current and noise via heterostructure fabrication.
- Demonstrated stability and high performance surpassing previous materials.

## Abstract

A long-wavelength infrared (IR) photodetector based on two-dimensional materials working at room temperature would have wide applications in many aspects in remote sensing, thermal imaging, biomedical optics, and medical imaging. However, sub-bandgap light detection in graphene and black phosphorus has been a long-standing scientific challenge because of low photoresponsivity, instability in the air and highdark current. In this study, we report a highly sensitive, air-stable and operable long-wavelength infrared photodetector at room temperature based on PdSe2 phototransistors and its heterostructure. A high photoresponsivity of ~42.1 AW-1 (at 10.6 {\mu}m) was demonstrated, which is an order of magnitude higher than the current record of platinum diselenide. Moreover, the dark current and noise power density were suppressed effectively by fabricating a van der Waals heterostructure. This work fundamentally contributes to establishing long-wavelength infrared detection by PdSe2 at the forefront of long-IR two-dimensional-materials-based photonics.

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Source: https://tomesphere.com/paper/1902.02199