Title: 2D glassy-graphene device arrays with photodetection and VOC sensing capabilities

Abstract

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 novel 2D glassy-graphene1,3 that meets similar property requirements for the two functionalities. An appropriate bandgap arising from the distorted lattice structure enables glassy-graphene to exhibit similar or even improved photodetection and chemical sensing capability, compared to pristine graphene. Due to strong interactions between glassy-graphene and the ambient atmosphere, the devices are less sensitive to photoinduced desorption than graphene. Consequently, the few-layer glassy-graphene device delivers positive photoresponse, with a responsivity of 0.22 A/W and specific detectivity reaching 1010 Jones under 405 nm illumination. Moreover, the intrinsic defects and strain in glassy-graphene can enhance the adsorption of analytes, leading to good chemical sensing performance. Specifically, the extracted signal-to-noise-ratio (SNR) of the glassy-graphene device for detecting acetone is 48, representing more than 50% improvement over the graphene counterpart. Additionally, bias voltage and thickness dependent VOC sensing features are identified, indicating the few-layer glassy-graphene is more sensitive. This study successfully demonstrates the potential of glassy-graphene for integrated photodetection and chemical sensing, providing a promising solution for multifunctional applications further beyond.