Multifunctional two-dimensional glassy graphene devices for vis-NIR photodetection and volatile organic compound sensing

Multifunctional devices are of great interest for integration and miniaturization on the same platform, but simple addition of functionalities would lead to excessively large devices. Here, the photodetection and chemical sensing device is developed based on two-dimensional (2D) glassy-graphene that meets similar property requirements for the two functionalities. An appropriate bandgap arising from the distorted lattice structure enables glassy graphene to exhibit comparable or even improved photodetection and chemical sensing capability, compared with pristine graphene. Due to strong interactions between glassy graphene and the ambient atmosphere, the devices are less sensitive to photoinduced desorption than the ones based on graphene. Consequently, the few-layer glassy graphene device delivers positive photoresponse, with a responsivity of 0.22 A W-1 and specific detectivity reaching similar to 10(10) Jones under 405 nm illumination. Moreover, the intrinsic defects and strain in glassy graphene can enhance the adsorption of analytes, leading to high chemical sensing performance. Specifically, the extracted signalto-noise-ratio of the glassy graphene device for detecting acetone is 48, representing more than 50% improvement over the device based on graphene. Additionally, bias-voltage- and thickness-dependent volatile organic compound (VOC) sensing features are identified, indicating the few-layer glassy graphene is more sensitive. This study successfully demon- strates the potential of glassy graphene for integrated photodetection and chemical sensing, providing a promising solution for multifunctional applications further beyond.

Automated summary

A multifunctional device based on two-dimensional glassy graphene has been developed for integrated photodetection and chemical sensing, demonstrating comparable or improved performance compared to pristine graphene. The glassy graphene device shows less sensitivity to photoinduced desorption and enhanced adsorption of analytes, leading to positive photoresponse and improved chemical sensing capabilities. This study highlights the potential of glassy graphene for multifunctional applications beyond current limitations.