A synergistic effect of ZnO low dimensional rods/PEDOT: PSS hybrid structure for UV radiation detection

UV sensors in wearables help outdoor users protect their skin by monitoring exposure. Detecting UV light is crucial for safety, given its potential hazards. Our research has developed an efficient methodology for creating UV sensors. This method is characterized by a streamlined, one-step solution-processed approach, prioritizing simplicity in fabrication, heightened responsiveness, and cost-effectiveness as key attributes. We designed a platform utilizing the synergistic effects of a hybrid network, incorporating the conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) and Zinc oxide (ZnO) low dimensional rods (LDR) at varying concentrations of ZnO relative to PEDOT: PSS. Using a straightforward drop-cast technique, the hybrid film was applied to a p-type silicon wafer. Incorporating ZnO LDR into PEDOT: PSS causes the LDR to become integrated into the polymer matrix, ultimately resulting in a consistently distributed film. A thickness profilometer was utilized to measure the thickness of the hybrid film, which was around 1.4 μm. FE-SEM was employed to elucidate the intricate morphological features of ZnO LDR and to investigate the synergistic hybrid composition formed by the combination of PEDOT: PSS and ZnO. The micrographs provided valuable insights into the size, shape, and distribution of ZnO LDR, facilitating a comprehensive understanding of their morphological characteristics. The length of the LDR, on average, was roughly 9.5 μm, and their diameter was approximately 0.575 μm. Furthermore, the formation of the hybrid film was verified using UV-Vis spectroscopy, revealing distinct bands originating from both PSS in PEDOT: PSS and ZnO. Upon UV radiation exposure to the hybrid film, conductivity changes were measured in both UV on and off conditions. The most successful device with 10 wt% of ZnO in PEDOT: PSS exhibited a response of around 7.5%.