Tribo-piezoelectric Hybrid Nanogenerators Based on ZnO Nanorods and CsPbBr₃ Nanoparticle/PVDF-HFP Films for Self-Powered Photodetectors

Here, we report the development of a tribo-piezoelectric hybrid nanogenerator (STPHNG) based on a ZnO-CsPbBr 3 /poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) system for the photodetection in the ultraviolet (UV) to the visible region. The encapsulation of chemically synthesized CsPbBr 3 nanoparticles (∼10 nm) in PVDF-HFP polymers is proven to be an excellent strategy for achieving STPHNG with long-term stability. Apart from encapsulating the CsPbBr 3 nanoparticles from the ambient environment, CsPbBr 3 /PVDF-HFP offers a suitable piezoelectric output to enhance the triboelectric characteristics by 5 times when brought in contact with ZnO nanorods having an average diameter of ∼55 nm. Again, the photodetection characteristics of the hybrid nanogenerator were realized from the variation in the STPHNG output under UV or visible light. The light-induced modification in the output is a consequence of the screening effect of tribo-charges, which not only lowers the open-circuit voltage but also modifies the inherent capacitance of the nanogenerator. The superior photoresponsivity values of ∼6.59 × 10 4 and ∼3.67 × 10 4 V/W for visible and UV light, respectively, originate from the outstanding optical absorption properties and the shielding of tribo-charges in the active materials. Finally, the real-time UV photodetection and data transmission of the wearable STPHNG were demonstrated upon operating through the finger movement of a user. The demonstration of output modification, excellent photodetection, and long-term stability with the ZnO-CsPbBr 3 /PVDF-HFP system may build the foundation for futuristic, wearable, cost-effective photodetectors with superior efficiency and longevity.