Visible-blind UV photodetectors using a polymer/ZnO nanocomposite thin film

• Published in: Sensors and actuators. A. Physical. Vol. 338; p. 113495
• Main Authors: Hanna, B., Pillai, Lekshmi R., Rajeev, Kavya, Surendran, K.P., Unni, K.N.N.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-05-2022; Elsevier BV
• Subjects: Atomic force microscopy; Beta phase; Difluorides; Electrode materials; Electrode polarization; Electrodes; Ferroelectric materials; Ferroelectricity; FTIR; Illumination; Infrared spectroscopy; Light; Nanocomposite; Nanocomposites; Nanoparticles; Photoluminescence; Photometers; Polymer films; Polymers; Polymethyl methacrylate; Polystyrene resins; Responsivity; Silver; Thin films; Ultraviolet radiation; UV photodetector; Vinylidene; X-ray diffraction; Zinc oxide; Zinc oxides; ZnO; β phase; β phase; Nanocomposite; ZnO; UV photodetector; FTIR; Responsivity
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2022.113495

We report the fabrication and characterization of visible-blind UV photodetectors using thin films of polymer/zinc oxide (ZnO) nanocomposites. Polymer-ZnO nanocomposites based on three polymers, poly(methyl methacrylate)(PMMA), polystyrene(PS) and poly(vinylidene difluoride-trifluoroethylene(P(VDF-TrFE)) were studied. The electrical response of the detectors to 365 nm and 254 nm UV light illumination was probed. P(VDF-TrFE)/ZnO nanocomposite-based device exhibited the best performance compared to the other devices, possibly due to its ferroelectric property. Further, we prepared P(VDF-TrFE)/ZnO nanocomposite with different wt% of ZnO nanoparticles and characterized them by atomic force microscopy (AFM), X-ray diffraction (XRD), fourier transform- infrared spectroscopy (FTIR), UV-Visible absorption spectroscopy, and Photoluminescence (PL). XRD and FTIR studies confirmed the formation of the β phase of P(VDF-TrFE) in pristine polymer films and their nanocomposites. The influence of the top electrode material on the photodetector performance of nanocomposites was studied. P(VDF-TrFE)/5 wt% ZnO nanocomposite with Ag top electrode exhibited the best performance with on-off ratio, 1.4 × 104; responsivity, 14.43 A/W; linear dynamic range, 83.09 dB and detectivity, 2.27 × 1013 jones under 365 nm light illumination. The ferroelectric polarization mechanism of P(VDF-TrFE) and the choice of electrode play an important role in the performance of the devices.
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•ZnO/Polymer nanocomposites were prepared with 3 polymers; PMMA, PS and P(VDF-TrFE).•All nanocomposite films are visible-transparent with reduced surface defects.•P(VDF-TrFE)/ZnO shows the best photoresponse in the UV region.•The concentration of ZnO and the choice of electrodes influence the photoresponse.•Ferroelectric nature of P(VDF-TrFE) helps improve the performance.