Structural, Electrical and Optical Properties of PVC/ZnTe Nanocomposite Thin Films

Abstract

ZnTe nanoparticles (NPs) were synthesized using hydrothermal method and then were dispersed in poly(vinyl-chloride) (PVC) to prepare hybrid PVC/ZnTe nanocomposite thin films which were deposited on glass substrates by the dip coating technique. Structural, optical and electrical properties of films were investigated by different techniques. XRD analysis revealed that synthesized ZnTe NPs have a cubic structure and a nanoscale size,while pure PVC films have a weak degree of crystallinity and exhibit a broad diffraction peak at low angles. The PVC/ZnTe nanocomposite thin films display an intense diffraction peak corresponding to the plane ( 220) which indicates a preferred orientation of ZnTe nanocystallites along crystallographic axis [220]. This texture was also showed by the atomic force microscopy micrographs.The analysis by FT-IR and Raman vibrational spectroscopies confirmed the incorporation of ZnTe NPs in the PVC matrix.The ZnTe/PVC nanocomposites thin films have an optical transparency over 80 % in the visible range and an optical gap close to 4.07 eV. Discrepancies with respect to the gap of pure PVC (red shift) and bulk ZnTe (blue shift) are due to the effect of the interaction between the ZnTe NPsand the PVC matrixand alsoto the nanometric size of the ZnTe crystallites. Photoluminescence (PL) spectra showed an enhanced blue emission at 466 nm,a green emissionat 522 nm and a strong red emission at 686 nm. Thus the incorporation of oriented ZnTe NPs induced a new optical behavior of the PVC polymer matrix.Electrical measurements indicate a decrease of electrical resistivity of PVC/ZnTe nanocompositesas ZnTe NPs concentration increases.

Effect of CdSSe nanoparticles on the structural, surface roughness, linear, and nonlinear optical parameters of polyvinyl chloride films for optoelectronic applications

“…The broad starching vibration of the -OH groups is observed at 3459 cm −1 . The band at 2361 cm −1 is related to CO 2 from the atmosphere [28]. The band at 1746 cm −1 is attributed to the C=O bond [34] which shifted from its position to lower wavenumber at ∼ 1741, 1735, and 1740 cm −1 for 1%, 2%, and 3% CdSSe-PVC films, respectively.…”

“…Recently, El-Hachemi et al [28] reported a PVC system reinforced with different concentrations of ZnTe nanoparticles and found that the optical properties of the prepared system improved with increasing the ZnTe concentration in the matrix. Rouabah et al [23] investigated the PVC-CdS system's the optical properties and concluded that the PVC-CdS films are transparent in visible-light, besides tuning the optical parameters.…”

PVC polymer/ZnO/NiO/Co3O4 nanocomposites: Toward improved optical properties

“…It is noticeable that the FL intensity is small for λ exc = 317 nm and highest for λ exc = 380 nm. The characteristic emission band of PVC excimer fluorescence corresponding to electronic π*–π transition 71 appeared at 395 nm for excitation λ exc = 317 nm and shifted to 408 and 468 nm for λ exc = 380 and 434 nm excitation wavelengths. The shoulder peaks appearing right to the main band may be assigned to π*–n transition or trapped energy levels resulting from impurities defects 71 .…”

“…The characteristic emission band of PVC excimer fluorescence corresponding to electronic π*–π transition 71 appeared at 395 nm for excitation λ exc = 317 nm and shifted to 408 and 468 nm for λ exc = 380 and 434 nm excitation wavelengths. The shoulder peaks appearing right to the main band may be assigned to π*–n transition or trapped energy levels resulting from impurities defects 71 . The small emission peak at 570 nm, Figure 10B, appeared only for high NiO content and assigned to NiO.…”

“…The shoulder peaks appearing right to the main band may be assigned to π*-n transition or trapped energy levels resulting from impurities defects. 71 The small emission peak at 570 nm, Figure 10B, appeared only for high NiO content and assigned to NiO. Surprising, loading PVC with the composite oxides quenches the FL emission intensity for λ exc = 317 nm at all values of (x), Figure 10A, while upon excitation with λ exc = 380 or 434 nm the FL intensity increases with NiO content and decreases or remains constant with Co 3 O 4 content, Figure 10B, C.…”