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In this work, the effect of carbon quantum dots (CQDs) on the optical and electrical properties of polyvinylidene fluoride (PVDF) has been investigated. Different weight percent (0, 1, 3, 5 and 10 wt%) ratios of CQDs/PVDF nanocomposite films were prepared using solution casting technique. The morphological properties of CQDs were examined using a t...
Citations
... The perovskite thin film exhibits powerful absorption from the visible range down to the close infrared wavelengths, with the absorption onset at ca. 750-785 nm. Figure 4a displays the Tauc plots that were created from the UV-IR spectra to estimate the band gap of all the Sb-doped samples. The linear portions of ðahtÞ 2 vs incident photon energy (E) were extrapolated to the horizontal axis using Tauc's relation to derive the band gap energies [36,37]: ...
In this paper, we have shown that Sb has been doped into the light-absorbing methylammonium lead iodide (CH3NH3PbI3) perovskite. We had anticipated that the introduction of antimony (Sb³⁺) as a dopant in perovskite would result in improved light-absorbing properties for use in photovoltaic cells, including longer carrier lifetimes and an ideal band gap. We used a simplified and cost-effective method to fabricate thin films of CH3NH3PbI3 perovskite doped with antimony, which were deposited onto cleaned FTO substrates using a modified two-step spin-coating process. To evaluate the characteristics of these films, we utilized three different techniques: XRD, SEM, and UV-Vis spectroscopy to analyze their structural, optical, and dielectric properties. It was discovered that the optical band gap varied with Sb-doping concentration. The XRD data showed that there were no additional peaks, suggesting that Sb was able to partially replace Pb²⁺ successfully. However, the crystallinity increased with doping up to 1.0%, but decreased at higher concentrations. This finding aligns with the SEM morphology of the resulting films, which exhibited regular crystallites on a more even, compact, and complete surface. Finally, the IV curve showed improvement in the performance of the fabricated PSCs by increasing the Sb-doping ratio until 2.0% but decreased at the high concentration of 3.0%.
... This goal can be achieved by either blending several homopolymers or filling them with specific materials to match specific uses. These applications comprise optoelectronics, light emitting diodes (LEDs), photovoltaics, shielding, energy storage, bio and medical ones [8][9][10][11][12][13][14][15][16][17][18]. Particularly, polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) are greatly appreciated due to their novel characteristics over other polymers such as their eco-environmentally, biodegradability, non-toxicity and water solubility [8,11,12,19,20]. ...
The functional properties of polyvinyl pyrrolidone/polyvinyl alcohol (PVP/PVA) blend incorporated with non-stoichiometric tin sulphide (SnS) have been explored for optoelectronic devices. PVP/PVA blend incorporated with non-stoichiometric Sn/S ratios (1:0.8–1:1.2) of 1.0 wt.% SnS were prepared by casting method. The effect of the non-stoichiometric Sn/S ratio of SnS on the structure, optical and photoluminescent (PL) properties of the composite was examined by Fourier transform infrared, UV-visible-NIR and photoluminescence spectrophotometers. The optical band gap energy decreases, while Urbach energy increases via SnS incorporation. The lattice dielectric constant is improved about three times, while the free carriers’ concentration to the effective mass is enhanced by one order of magnitude due to SnS1.2 incorporating. PL measurements reveal that PVP/PVA blends incorporated with SnS could emit spectra in the visible region. Designing the optical and photoluminescent properties of the PVP/PVA blend reveal their role in advanced optoelectronic devices.
... The decrease in the barrier height can be explained by the increase in the reverse bias current of the device and the decrease in the ideality factor by the increased partial current due to UV light. The changes in the carbonaceous structure relative to the device in the carbon-free device can be attributed to the formation of new energy states from carbon in the PVP polymer and the increase in DC conductivity [32] and the mobility of the carriers [10]. Furthermore, it has been reported that the carbon nanomaterials give an efficient charge transport medium in the hybrid photodetectors [33]. ...
Both Polyvinylpyrrolidone (PVP) and matrix-polymer of carbon (C)-PVP fibers (Fs) composites were synthesized by using the electrospinning technique and deposited onto the p-Si wafers to obtain PVP Fs/p-Si and C-PVP Fs/p-Si devices. The ultraviolet/Visible (UV/Vis) photodetector performance of both devices was compared. Both devices gave self-powered mode and with increasing the visible light intensity, the photocurrents of both devices increased. Besides, it was observed that the optical performance of the device containing C was better than the PVP Fs/p-Si device in both visible and UV lights. This was attributed to the high absorption properties of carbon and the increase in conductivity in the PVP due to carbon fibers. Furthermore, it is thought that the electric field formed in the carbon-PVP interaction and C-PVP/p-Si interface improves the optical properties of the device by increasing the exciton separation efficiency. Under the self-powered mode, the C-PVP Fs/p-Si device exhibited a maximum detectivity and ON/OFF ratio of 5.60×1010 Jones and 53764, respectively for UV light of 365 nm. Under 100 mW visible light, these values were determined as 1.01×1010 Jones and 9739, respectively, at V=0. In addition, from the obtained noise-equivalent power (NEP) values, it was concluded that weaker signals can be detected under UV light (6.94×10-14w/Hz1/2, at -2 V) than visible light (3.32×10-13 w/Hz1/2, at -2 V) for C-PVP Fs/p-Si.
... The optical properties of CQDs are currently being investigated in sufficient detail [7,11]. There is some research on the influence of CQDs on the optical and electrical properties of polyvinylidene fluoride polymer for optoelectronic applications [12]. Similar studies on the effect of the material on the electrical properties have also been carried out for carbon nanotubes and graphene/PEDOT:PSS composite [13,14]. ...
Cqd/pedot:
PSS composites were prepared via the hydrothermal method from glucose carbon quantum dots (CQDs) and an aqueous solution of PEDOT:PSS conducting polymer and their electrical and optical properties were investigated. The morphology and structure of these samples were investigated by AFM, SEM, EDX, and EBSD. It was found that the CQDs and CQD/PEDOT:PSS composites had a globular structure with globule sizes of ~50-300 nm depending on the concentration of PEDOT:PSS in these composites. The temperature dependence of the resistivity was obtained for the CQD/PEDOT:PSS (3%, 5%, 50%) composites, which had a weak activation character. The charge transport mechanism was discussed. The dependence of the resistivity on the storage time of the CQD/PEDOT:PSS (3%, 5%, 50%) composites and pure PEDOT:PSS was obtained. It was noted that mixing CQDs with PEDOT:PSS allowed us to obtain better electrical and optical properties than pure CQDs.
Cqd/pedot:
PSS (3%, 5%, 50%) composites are more conductive composites than pure CQDs, and the absorbance spectra of CQD/PEDOT:PSS composites are a synergistic effect of interaction between CQDs and PEDOT:PSS. We also note the better stability of the CQD/PEDOT:PSS (50%) composite than the pure PEDOT:PSS film.
Cqd/pedot:
PSS (50%) composite is promising for use as stable hole transport layers in devices of flexible organic electronics.
... In recent years, polymers' composites (PCs) have been gained exclusive concern due to their fundamental role in various applications in transportations, optoelectronics, entertainment, medicine, packaging and shielding [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. This exceptional concern in PCs arises due to their unique characteristics including optical, electrical, mechanical and structural properties. ...
In this study, the structural, linear and nonlinear optical performance of PVA/graphene polymeric composites (PVA/Gr PCs) incorporated with lead oxide (Pb3O4) have been modified by exposing with gamma irradiation (γ-irradiation). Pb3O4 incorporated PVA/Gr PCs were prepared by the solution casting procedure and exposed to different γ-irradiation doses (50, 100, 150, 200 and 250 kGy). The structural and optical properties of the irradiated PCs were examined by FT-IR, XRD and UV–visible spectrophotometer. The XRD analysis reveals that the semi crystallinity feature of the PCs decreases with increasing the irradiation dose. The UV–Vis.-NIR measurements show that the optical absorbance of the PCs increases upon increasing the irradiation dose to 250 kGy. The direct optical bandgap energy shrinks from 5.26 eV (non-irradiated PC) to 4.82 eV (250 kGy irradiated PC). Obvious enhancement in the optical parameters (refractive index, dielectric (real εr, imaginary εi) constant and optical conductivity is achieved. Furthermore, the first-order linear susceptibility (χ⁽¹⁾), third-order nonlinear susceptibility (χ⁽³⁾) and nonlinear refractive index (n2) of Pb3O4 PCs are also tailored via controlling the γ-irradiation dose. This enhancement in the linear and nonlinear optical parameters of PCs was pronounced in the UV region. For instance, at 285 nm, χ⁽¹⁾ increases from 0.19 to 0.45 and χ⁽³⁾ increases from 2.25 × 10⁻¹³ to 6.76 × 10⁻¹² esu as the γ-irradiation dose is increased from 0 to 250 kGy. These findings nominate the potential applications of Pb3O4 PCs in dosimetry and shielding devices.
... There are also some studies conducted on the optics properties of PVDF, PVDF-copolymers, PVDF-Blends and PVDF-nanocomposites, for its quite large optical windows (200~1200 nm), good linear and non-linear optical (NLO) properties. The well-known applications of PVDF-nanocomposites are used for optical frequency conversion materials, memory and limiting devices [22][23][24][25][26], which are doped with nanoparticles, such as ZnO [27], CuO [28], ZrO 2 [29], HfO 2 [30], reduced graphene oxide (RGO) [31,32], Carbon Nanotubes [33,34], Carbon Quantum Dots [35], cellulose [36], Li 4 Ti 5 O 12 [37], and so on. ...
... displays the comparison of the collapse and surface pressure in this work and some published work. In order to obtain the exact collapse pressure, 12 targetvalues have been set in the π-A experiment for5,10,15,20,25,35,40,45,50,55, 60 and 65 mN/m, respectively. ...
The films of vinylidene fluoride and trifluoroethylene (P(VDF-TrFE)) are widely used in piezoelectric tactile sensors, vibration energy harvesters, optical frequency conversion materials and organic photo-voltaic devices because of high electroactive, good optical and nonlinear optical properties, respectively. In this work, the multilayer structured ultrathin films were fabricated by the Langmuir–Blodgett technique, and the thickness per layer can be controlled accurately. It was found that as the collapse pressure of P(VDF-TrFE) (25:75) and the optimal dipping value are 60~70 mN/m and 15 mN/m, respectively, a high-density film can be obtained due to the compression of molecules. The surface topography and optical properties of the LB films were characterized by X-ray diffraction, white light interferometer and variable-angle spectrum ellipsometer. It was observed that the films are transparent in the visible region and IR-band, but show a high absorption in the UV band. Besides, the transmittance of the films ranges from 50% to 85% in the visible region, and it linearly decreases with the number of monolayers. The average thickness of per deposition layer is 2.447 nm, 2.688 nm and 2.072 nm, respectively, under three measurement methods. The calculated refractive index ranged from 1.443 to 1.598 (600~650 nm) by the Cauchy-model.
... 15 Carbon dots have been used in bio-imaging 16 and white LED (WLED) 17 applications, and for the identication/detection of metal ions, 18,19 adulterants, 20 contaminants, 21 bacteria, 22 and other microorganisms. Additionally, these nanostructures have also been incorporated into different polymers such as poly(methyl methacrylate) (PMMA) and polystyrene (PS), 23 polyvinyl alcohol (PVA), 24-28 and polyvinylidene uoride (PVDF) [29][30][31][32][33] to create lms and membranes for different applications. ...
The ultraviolet-A (UVA) radiation from sunlight that reaches the earth's surface can induce premature aging, immunosuppression, and skin cancer. Commercial sunscreen products offer limited information regarding protection against UVA light. Therefore, proposing new and practical alternatives to evaluate the UVA protection capacity of commercial sunscreens is highly imperative. This work presents a novel methodology for evaluating the quality of sunscreens using polyvinylidene fluoride (PVDF) based films doped with plant derived photoluminescent carbon dots (CDs). The bluish white light emitting (under UVA exposure) PVDF/CD films were used to evaluate the UVA protection capacity of 8 different commercial sunscreens. The evaluation of UVA protection is based on the fluorescence attenuation observed with the films coated with sunscreens. In addition, visual evaluation of the UVA protection capacity of the sunscreens and commercial glasses, using the same films and a commercial UV lamp at 365 nm, has also been demonstrated. Two sunscreens with limited UVA protection were identified using the proposed simple evaluation mechanisms without conventionally used expensive instruments and complex methodologies. Additionally, the capacity of PVDF/CD material has been explored for the possible fabrication of WLEDs with cool light emission.
... Their attractive characteristics including their low-cost, abundance, and flexibility. Most polymers are considered non-toxic and could easily play the role of host matrices for different sorts of fillers [1][2][3][4][5][6][7][8]. Improving the polymers' optical, electrical and mechanical properties can be achieved via implanting limited concentrations of fillers to match desired applications. ...
In this study, the role of iron sulfide (FeS) content on the structural and optical properties of graphene/polyvinyl alcohol (Gr/PVA) blend has been examined for environmental-friendly applications. Gr/PVA blend filled with FeS (0 to 10 wt%) were equipped using the casting technique. The prepared samples were studied via a scanning electron microscope, X-ray diffractometer, FT-IR and UV–visible-NIR spectrophotometers. XRD analysis shows that the crystallinity increases with increasing FeS concentration in the host Gr/PVA blend. UV–visible-NIR analysis shows that the direct optical bandgap of composite blends shrinks from 5.37 to 4.68 eV as FeS content is increased to 10 wt%. Also, it confirms that the refractive index and optical conductivity of Gr/PVA blend could be significantly enhanced via FeS filling. FeS filled Gr/PVA blends are recommended eco-friendly applications.
... α and K of the irradiated EBT2 films are determined from the UV-vis.-NIR transmittance T measurements as [21,22]: ...
The effect of the solar irradiation on the structure and optical properties of Gafchromic films has been investigated for bio applications. Gafchromic (EBT2 series) films were exposed to different irradiation times (0–120 min) via a solar simulator under AM1.5 conditions. The structural variations of the prepared films were examined using FT–IR spectrophotometry. UV–visible-NIR spectra measurements were recorded to explore the optical properties. The absorbance spectra of the irradiated films increase as the irradiation time increases up to 120 min. The obtained optical bandgap of the prepared films decreases from 2.45 eV to–2.24 eV as the irradiation time increases from 0 to 120 min. Moreover, the increase in the irradiation time up to 120 min. results in an increase in the refractive index (n) and the dielectric constant values in the investigated UV–visible-NIR regions. According to our knowledge, this is the first time that the effect of the solar irradiation on the Gafchromic films has been investigated. Our novel results greatly recommend the use of the Gafchromic films (EBT2 series) in sensors, dosimetry and bio-applications.
... These features involve the structural, optical, electrical and mechanical properties. The superiority of polymer composites over traditional organic and inorganic materials qualifies them to be active candidates in various applications [1][2][3][4]. Some of these applications are included in communications, industry, medicine and electronics. ...
... Alharthi et al. [3] explored the electrical and photoluminescence behaviors of Ag 2 S/PVA for visible-light optoelectronics. Also, Fe 2 O 3 nanoparticles, carbon quantum dots and other dopants were used to enhance the physical properties of host polymers for multi applications [1,[7][8][9][10]. Polyvinylalcohol (PVA), chitosan and polyvinylpyrrolidine (PVP) polymers play the leader-role as host matrices for dopants material due to their novel properties as low-cost, water-solubility, non-toxicity, bio-compatibility and hence environment-friendly. ...
The optical properties of polyvinylpyrrolidine (PVP) polymer have been enhanced using ternary Zn1-xSnxS as a filler for UV-region optical applications. Solution casting technique is used to prepare different Sn molar ratios (x: 0–0.3) in Zn1-xSnxS filled PVP polymeric composite films (1.0 wt.%). SEM, FT-IR and UV–visible-NIR spectrophotometry is utilized to characterize the optical properties of the plain PVP and polymeric composite films. SEM images reveal the homogeneous dispersion of the filler (Zn1-xSnxS) in the host PVP matrix. The FT-IR spectroscopic measurements ensure the successful interaction of ternary Zn1-xSnxS material and the host PVP polymer. The cut off transmittance edge is shifted from 260 nm (host PVP) to 390 nm (polymeric composite). The direct optical energy bandgap of the prepared polymeric composite films are shifted from 4.78 eV (plain PVP) to 3.45 eV for Zn0.7Sn0.3S polymeric composite film. An enhancement of the refractive index (n) and the optical conductivity (σopt.) of the polymeric composite films is achieved as compared with those of the plain one. The single oscillator (E0) and dispersion (Ed) energies of the polymeric composite films were determined using Wemple and DiDomenico (WDD) model. The prepared polymeric composite films are strongly recommended for UV-region optical applications.
