Self-Powered Flexible TiO2 Fibrous Photodetectors: Heterojunction with P3HT and Boosted Responsivity and Selectivity by Au Nanoparticles

A novel inorganic-organic heterojunction (TiO2/P3HT (poly(3-hexylthiophene)) is easily prepared by a combination of anodization and vacuumed dip-coating methods, and the constructed flexible fibrous photodetector (FPD) exhibits high-performance self-powered UV-visible broadband photoresponse with fast speed, high responsivity, and good stability, as well as highly stable performance at bending states, showing great potential for wearable electronic devices. Moreover, Au nanoparticles are deposited to further boost the responsivity and selectivity by regulating the sputtering intervals. The optimal Au/TiO2/P3HT FPD yields an approximate to 700% responsivity enhancement at 0 V under 350 nm illumination. The sharp cut-off edge and high UV-visible rejection ratio (approximate to 17 times higher) indicate a self-powered flexible UV photodetector. This work provides an effective and versatile route to modulate the photoelectric performance of flexible electronic devices.