SILAR deposited cadmium sulphide (CdS) over graphitic carbon nitride (g-C3N4) based photo-enhanced triboelectric nanogenerator for self-powered visible light photodetector

Abstract

Self-powered visible-light photodetectors have gained prominence as sustainable solutions across multiple domains, including optical communication systems, biomedical imaging, and optical interconnections. In this study, we presented a self-powered visible-light photodetector in the form of a triboelectric nanogenerator (TENG), which comprises of g-C3N4/CdS over the indium tin oxide coated poly(ethylene terephthalate) (ITO/PET) sheet and aluminum. Firstly, the as-synthesized g-C3N4 was coated over ITO/PET and thereafter the CdS layer was deposited over g-C3N4 layer by using Successive Ionic Layer Adsorption and Reaction (SILAR) method. The formation of CdS thin layer has been confirmed through various characterization techniques, including SEM (Scanning Electron Microscopy), XRD (X-ray Diffraction), and Raman spectroscopy. The as-fabricated TENG exhibits 29.6 V of open circuit voltage (Voc) and 0.55 µA short circuit current (Isc), when subjected to force through finger tapping. Furthermore, the TENG demonstrates a calculated power density of 2.16 µW/cm2 with an external load of 45 MΩ. The TENG’s output performance achieved a significant improvement, reaching 55 V Voc, when exposed to visible light. This enhancement is credited to the mutual coupling effect and enhanced interfacial interactions, fostering a charge-trapping mechanism. The exceptional efficiency of our fabricated TENG establishes itself as a highly productive hybrid system for developing self-powered system, particularly serving as a self-powered visible-light photodetector.