Photosensitive RFID sensor based on ZnO/GO/CdS nanocomposite

A chipless radio frequency identification (RFID) photosensitive sensor composed of zinc oxide (ZnO) / graphene oxide (GO) / cadmium sulfide (CdS) nanocomposites is designed and fabricated for remote monitoring of light in the environment. The label consists of a dielectric layer, a resonant structure, and a sensitive layer. The dielectric layer is made of inexpensive epoxy resin. By replacing the parallel plate capacitance of the traditional ELC resonator with the interdigital capacitance (idc), an ELC idc resonator with a larger capacitance per unit area is obtained and optimized by HFSS simulation. The label is evaluated using a vector network analyzer, and the experimental results confirm the feasibility of the photosensitive label. In the light environment of 0–49 klx, the sensitivity of the photosensitive label is 895.31 Hz/lx thus meeting the requirement for the monitoring of environmental light.