In-Situ Piezoelectric Effect for Augmenting Performance of Self-Powered ZnO-Based Photodetector

Abstract

In this study, an in-situ piezoelectric effect is integrated into a photoactive region to develop a self-powered ultraviolet photodetector based on a p-n junction of ZnO@Polyvinylidene fluoride (PVDF) and poly [9,9-dioctylfluorene-co-N-[4-(3-methylpropyl)]-diphenylamine] (TFB). A ZnO@β-PVDF nanocomposite is fabricated using PVDF with the β-phase as the polymer matrix and ZnO nanoparticles as fillers. The strong piezoelectricity of β-PVDF can facilitate the separation and transport of photogenerated electrons in the depletion area and considerably reduce the dark current when the device is polarized with an external bias, resulting in an improvement in the on/off ratio and detectivity. Under 365-nm UV illumination, the as-fabricated device exhibits a high detectivity of 4.99 × 1011 Jones, an excellent on/off ratio (up to 2.75 × 104), and a fast response speed of 46/53 ms (rise/fall times). The device functions stably over approximately 1000 continuous on/off cycles and exhibits extremely long-lasting photostability when exposed to UV light. The findings demonstrate a promising strategy for enhancing the performance of photodetectors for industrial applications.