Graphene as Infrared Light Sensor Material

TL;DR

This study demonstrates that graphene synthesized via atmospheric CVD can serve as an effective IR light sensor, showing rapid transient responses and sensitivity influenced by temperature and hydrogenation effects.

Contribution

It introduces a method for fabricating graphene IR sensors with fast response times, highlighting the effects of temperature and hydrogenation on photoconductivity.

Findings

Graphene IR sensors exhibit transient response times around 100 times faster than CNT-based sensors.

Temperature increase reduces response and recovery times.

Hydrogenation decreases the photoresponse of graphene IR sensors.

Abstract

The infrared (IR) photoresponse of graphene synthesized by an atmospheric chemical vapor deposition (CVD) system using a mixture of hydrogen and methane gases was studied. The IR sensor devices were fabricated using graphene films transferred onto a SiO2 substrate by a lift-off process. The quality of graphene was investigated with Raman spectroscopy and optical microscopy. The photoresponse was recorded under the illumination of IR light of wavelength 850 nm and intensity of around 0.216 mW/cm^2. The effects of temperature and hydrogenation on photoconductivity were also studied. It was found that the transient response and recovery times decreased with the temperature increase. The hydrogenation effect also caused a significant decrease in the photoresponse of the device. Although the net change in the photoresponse for IR light was lower at low illumination intensity levels, the transient responses were observed around 100 times faster than the recently reported CNT-based IR sensors.