Augmented optical and electrical properties of PMMA-ZnS nanocomposites as emissive layer for OLED applications

• Published in: Optical materials 2019-05, Vol.91, p.470-481
• Main Authors: Nayak, Debashish, Choudhary, Ram Bilash
• Format: Article
• Language: English
• Subjects: Electrical; Emissive; OLEDs; Photoluminescence; Recombination; ZnS
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2019.03.040

We report the laboratory synthesis of Poly methyl methacrylate (PMMA)-Zinc sulfide (ZnS) nanocomposite via free radical polymerization method and its structural, optical, electrical, and dielectric properties for various concentration of ZnS nanoparticles. The formation of PMMA, ZnS and PMMA-ZnS nanocomposites was examined by X-ray diffraction technique, Fourier transforms infrared spectroscopy and FT-Raman spectrometer. Morphological structure of PMMA-ZnS nanocomposites showed the combination of pebbled and nanosphere like structure. The in-depth topological images were examined by transmission electron microscopy which indicated that the particles were fairly in good contact. The optimized and reduced band gap was calculated ∼3.30 eV. The photoluminescence spectra showed blue, green and yellow band with increased rate of e−-h+ recombination. The decay time of the PMMA-ZnS (5.0%) nanocomposite was ∼4.8413 ns, and the color purity was calculated ∼ 34.08%. The current density increased ∼249% which indicated the enhancement in conductivity. The dielectric properties of the PMMA-ZnS (5.0%) showed high dielectric constant with a very low dielectric loss. The reduction in optical band gap, high dielectric constant, and increased conductivity with increased in recombination rate confirmed that the as-prepared PMMA-ZnS nanocomposite can be used as an emissive layer in OLED devices. [Display omitted] •PMMA-ZnS nanocomposites were successfully synthesized via free radical polymerization method.•Optimum photoluminescence intensity was recorded for PMMA-ZnS (5.0%) nanocomposite.•Optimized band gap was recorded ∼3.30 eV and PMMA-ZnS nanocomposites showed blue shift.•Enhanced current density was calculated ∼110% as compared to ZnS.