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Unraveling the electrical properties of solution-processed copper iodide thin films for CuI/n-Si solar cells
摘要： The effects of temperature and liquid-phase iodination on the electrical property of spin coated CuI thin films have been investigated in details. The XRD study indicates that CuI thin films are polycrystalline in nature and I-doping enhances the crystal quality and size of the films. The SEM images show that the surface uniformity of the CuI thin films increases due to I-doping. The doping of iodine increases the conductivity as well as carrier concentration and mobility of the films as confirmed by Hall study. The temperature dependent resistivity of CuI film shows a sharp fall of resistivity at ~80 °C for un-doped films whereas this behavior disappears for I-doped films. The optical transmittance and band gap of the I-doped films also increases indicating high degeneracy of the films. These findings imply that I-doped spin coated CuI thin films are potential candidate for the solution-processed CuI/n-Si solar cells.
关键词： liquid-phase I-doped,spin coat,CuI thin films,switching-behavior,electrical properties
更新于2025-11-21 11:18:25
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Effect of rare earth Pr doping on core characteristics of electrodeposited nanocrystalline Cu2O films: a film for optoelectronic technology
摘要： Undoped and Pr doped Cu2O nanocrystalline ?lms were fabricated by the electrodeposition method. These ?lms were studied to investigate the formation, morphology, optical, and photoresponse properties on Pr doping concentrations (i.e., 0, 1, 3, and 5 wt%). Structural studies of the deposited Cu2O:Pr ?lms exposed the cubic crystal structure with polycrystalline nature. The crystallite size is decreased from 54 to 29 nm by increasing the Pr doping concentrations. The Raman peaks at 110, 147, 215, 413, and 633 con?rm the Cu2O phase and well matched with the XRD results. The morphological study shows that the pyramid-shaped particles are homogeneously arranged on the ?lm surfaces. The absorption is high for the ?lm deposited with the 5% Pr doping is due to the maximum thickness than the other ?lms. The calculated band gap values of Cu2O:Pr ?lms were reduced from 2.06 to 1.90 eV with raising the Pr doping level. PL spectra showed high intense emission peak at 617 nm which con?rms the NBE emission of Cu2O lattice. Index of refraction (n) and coef?cient of extinction (k) values were increased on increasing the doping concentration from 0 to 5%. From photosensitivity analysis, there is an increase of photoresponse behavior with respect to illuminated current.
关键词： Electrodeposition,Structural,Optical and electrical properties,Morphological
更新于2025-11-21 11:18:25
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Investigation of temperature and frequency dependence of electrical conductivity and dielectric behavior in CuS and rGO capped CuS nanocomposites
摘要： In this work, we develop a simple and low-cost strategy toward the one-pot synthesis of reduced graphene oxide (rGO) capped copper sulfide (CuS) nanocomposite through an obvious redox transformation reaction between Cu and graphene oxide (GO) without any additive. The prepared CuS and rGO capped CuS nanocomposite have been characterized by various physicochemical techniques for the observation of shape, morphology, and structure. It reveals the average size of the synthesized samples in the range of 10–30 nm with the hexagonal structure. The UV–vis absorption spectra exposed the strong absorption peak of CuS and rGO capped CuS composites in the range of NIR region was observed. The synthesized samples displayed high dielectric constant and electrical conductivity in a wide range of frequency (102–106 Hz). The effect of temperature on the electrical conductivity of the synthesized rGO capped CuS nanocomposite was also investigated. The excellent electrical conductivity performance is ascribed to the synergistic effect between CuS and rGO. As the temperature increases, the maximum electrical conductivity of rGO capped CuS composite was exponentially increased at high temperature. The synthesized composite with a high dielectric constant and electrical conductivity is a promising material in high capacitance, and further, it is used as electrode materials for supercapacitors and energy storage applications.
关键词： electrical conductivity,temperature effect,CuS nanocomposites,reduced graphene oxide,dielectric constant
更新于2025-11-21 11:18:25
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Band gap engineered zinc oxide nanostructures <i>via</i> a sol–gel synthesis of solvent driven shape-controlled crystal growth
摘要： A reliable sol–gel approach, which combines the formation of ZnO nanocrystals and a solvent driven, low shape-controlled, crystal-growth process to form well-organized ZnO nanostructures at temperature is presented. The sol of ZnO nanocrystals showed shape-controlled crystal growth with respect to the solvent type, resulting in either nanorods, nanoparticles, or nanoslates. The solvothermal process, along with the solvent polarity facilitate the shape-controlled crystal growth process, augmenting the concept of a selective adhesion of solvents onto crystal facets and controlling the final shape of the nanostructures. The XRD traces and XPS spectra support the concept of selective adhesion of solvents onto crystal facets that leads to yield different ZnO morphologies. The shift in optical absorption maxima from 332 nm in initial precursor solution, to 347 nm for ZnO nanocrystals sol, and finally to 375 nm for ZnO nanorods, evidenced the gradual growth and ripening of nanocrystals to dimensional nanostructures. The engineered optical band gaps of ZnO nanostructures are found to be ranged from 3.10 eV to 3.37 eV with respect to the ZnO nanostructures formed in different solvent systems. The theoretical band gaps computed from the experimental XRD spectral traces lie within the range of the optical band gaps obtained from UV-visible spectra of ZnO nanostructures. The spin-casted thin film of ZnO nanorods prepared in DMF exhibits the electrical conductivity of 1.14 × 10?3 S cm?1, which is nearly one order of magnitude higher than the electrical conductivity of ZnO nanoparticles formed in hydroquinone and ZnO sols. The possibility of engineering the band gap and electrical properties of ZnO at nanoscale utilizing an aqueous-based wet chemical synthesis process presented here is simple, versatile, and environmentally friendly, and thus may applicable for making other types of band-gap engineered metal oxide nanostructures with shape-controlled morphologies and optoelectrical properties.
关键词： electrical conductivity,ZnO nanostructures,optical band gap,shape-controlled crystal growth,sol–gel synthesis
更新于2025-11-19 16:56:42
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Electrical conductivity and conduction mechanisms in (Na <sub/>0.5</sub> Bi <sub/>0.5</sub> TiO <sub/>3</sub> ) <sub/>1?x</sub> (BiScO <sub/>3</sub> ) <sub/>x</sub> (0.00 ≤ <i>x</i> ≤ 0.25) solid solutions
摘要： The electrical properties of (Na0.5Bi0.5TiO3)1-x(BiScO3)x (NBT-BS, 0.00 ≤ x ≤ 0.25) solid solutions are established by ac impedance spectroscopy and electromotive force transport number measurements. The bulk conductivity decreases with increasing BS incorporation but the oxide-ion transport number remains high (≥0.85) over a wide compositional range 0.00 ≤ x ≤ 0.15 and drops to ≈0.7 for x ≥ 0.20. NBT-BS solid solutions can only present either predominant oxide-ion conduction or mixed ionic-electronic conduction behaviour, indicating that oxide-ion conduction cannot be fully eliminated by incorporation of BS. This is in contrast from our previous study where incorporation of ≈7% BiAlO3 (BA) can fully suppress the oxide-ion conduction in NBT. The conductivity–composition relationships of NBT-BS solid solutions are attributed to a competing effect from lattice expansion, which enlarges the channel for oxygen ion migration, with trapping between B-site acceptor ions, Sc'Ti, and oxygen vacancies, V??O, which decreases oxygen ion migration. Comparisons between NBT-BS, NBT-BA and NBT-BiGaO3 (BG) solid solutions suggest that small acceptor ions on the B-site are more effective in trapping oxygen vacancies and consequently more effective to suppress the oxide-ion conduction and thus reduce dielectric loss at elevated temperatures.
关键词： transport number,electrical conductivity,solid solutions,sodium bismuth titanate,oxide-ion conduction,conduction mechanisms,impedance spectroscopy,BiScO3
更新于2025-11-14 17:28:48
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Luminescence and electrical properties of Eu-modified Bi <sub/>0.5</sub> Na <sub/>0.5</sub> TiO <sub/>3</sub> multifunctional Ceramics
摘要： The Eu3+ modified Bi0.5Na0.5TiO3 (BNT) ceramics have been fabricated by the solid-state reaction method. The impact of Eu3+ doping on the structure, photoluminescence and electrical properties has been studied by XRD, SEM, PL spectra and LCR meter. X-ray diffraction analysis reveals that the crystal structure of the samples is well matched with the trigonal perovskite, and the optimal temperature of pre-sintering is 880°C. The Eu3+ doped BNT ceramics show excellent red fluorescence at 614nm corresponding to the 5D0→7F2 transition of Eu3+ under 466nm excitation and relatively long fluorescence lifetime. The BNT-0.02Eu ceramic density is up to 5.68g/cm3 and the relative density is up to 94.6% with sintering temperature 1075°C. The piezoelectric constant (d33) of samples has been significantly improved up to 110pC/N by Eu3+ doping. The BNT-0.03Eu ceramic pre-sintered at 880°C and sintered at 1050°C has good dielectric properties and excellent luminescence properties. Eu3+ doped BNT ceramics make it potential applications for novel integrated optical-electro and multifunctional devices.
关键词： luminescence,electrical properties,Bismuth sodium titanate (Bi0.5Na0.5TiO3),lead-free ceramics
更新于2025-11-14 17:28:48
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Improved densification behavior and energy harvesting properties of low-temperature sintered (Ba, Ca)(Zr, Ti)O3 piezoceramics with a CuO additive
摘要： Piezoelectric energy harvesting has recently attracted substantial interest because of its ability to provide sustainable power for devices that consume very small amounts of energy. In this work, we propose a CuO-doping strategy to develop environmentally friendly (Ba, Ca)(Zr, Ti)O3 (BCZT) piezoelectric energy harvesters with both low sintering temperatures and excellent power generation performance. The CuO dopant greatly promoted the densification behavior of BCZT ceramics, yielding a densified and fine-grained microstructure at a sintering temperature reduced by 125°C compared to that of undoped BCZT. Moreover, CuO addition substantially reduced the domain size compared to that of the undoped BCZT and thus facilitated domain switching in the ceramics. While maintaining the Curie temperature (Tc) at ~120oC, 0.50 mol% CuO-doped ceramics exhibited significantly enhanced electromechanical properties with a figure of merit d33×g33 of 6661×10-15 m2/N, high-field piezoelectric constant d33* of 873 pm/V, electromechanical coupling factor kp of 0.53 and energy conversion efficiency η of 97%. A high power density of 1.8 μW/mm3, which corresponds to a ~360% improvement relative to that of the undoped BCZT, was achieved from 0.50 mol% CuO-doped BCZT energy harvesters at 10 m/s2 acceleration. These findings suggest the tremendous potential of CuO-doped (Ba, Ca)(Zr, Ti)O3 piezoceramics in high-power-density energy harvesting applications.
关键词： A. Sintering,C. Electrical properties,D. BaTiO3,B. Microstructure
更新于2025-11-14 17:28:48
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Dielectric and Piezoelectric Properties of Textured Lead-Free Na0.5Bi0.5TiO3-Based Ceramics
摘要： This work provides a comparative study of the dielectric and piezoelectric properties of randomly oriented and textured 0.88Na0.5Bi0.5TiO3-0.08K0.5Bi0.5TiO3-0.04BaTiO3 (88NBT) ceramics. Textured ceramics were fabricated by template grain growth (TGG) method using NaNbO3 (NN) for templates. For textured ceramics with 4 wt% NN templates, a Lotgering factor of 96% and piezoelectric coe?cient d33 of 185 pC/N were obtained. Compared to the randomly oriented ceramics, textured ceramics show lower strain hysteresis (H = 7.6%), higher unipolar strain of 0.041% with corresponding large signal piezoelectric coe?cient d33* of 200 pm/V at applied ?eld of 2 kV/mm. This enhancement can be explained by the grain orientation along <001> direction by texturing, where an engineered domain con?guration is formed after polarization, leading to decreased hysteresis and increased piezoelectric property.
关键词： electrical conductivity,textured ceramics,template grain growth,piezoelectric materials
更新于2025-11-14 17:28:48
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Enhanced visible-light-driven photocatalytic activity of BiFeO3 via electric-field control of spontaneous polarization
摘要： Well-polarized BiFeO3 nanoparticles have been successfully prepared by a facile electrical poling method with the assist of a soluble organic-inorganic composite film. From XRD, TEM and SEM studies, no significant change in the crystal structure or morphology was detected after the electrical poling process. The visible-light driven photocatalytic process of poled BiFeO3 nanoparticles was accelerated by 2 times compared to unpoled BiFeO3. By combining time-resolved photoluminescence (PL), photoinduced silver deposition testing and photoelectrochemical measurements, it can be revealed that the enhanced photocatalytic performance of poled samples can be properly attributed to the promoted separation and prolonged lifetime of the photogenerated carriers caused by the ferroelectric polarization. These findings may offer a new route to promote the photocatalytic or photoelectric performances of BiFeO3 for advanced applications by adjusting the ferroelectric polarization.
关键词： BiFeO3 nanoparticles,Organic-inorganic composite film,Ferroelectric polarization,Electrical poling technology,Photocatalytic activity
更新于2025-11-14 15:24:45
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Fabrication of conductive fibrous scaffold for photoreceptor differentiation of mesenchymal stem cell
摘要： Conductive nanofibrous scaffolds with that can conduct electrical current have a great potential in neural tissue engineering. The purpose of this study was to survey effects of electrical stimulation and polycaprolactone/polypyrrole/multiwall carbon nanotube (PCL/PPY/MWCNTs) fibrous scaffold on photoreceptor differentiation of trabecular meshwork mesenchymal stem cells (TM‐MSCs). PCL/PPY/MWCNTs scaffold was made by electrospinning method. TM‐MSCs were seeded on PCL/PPY/MWCNTs scaffold and stimulated with a potential of 115 V/m. Scanning electron microscopy, transmission electron microscopy, and FT‐IR were used to evaluate the fabricated scaffold. Immunofluorescence and quantitative real‐time polymerase chain reaction were used to examine differentiated cells. Scanning electron microscopy, transmitting electron microscopy, and FT‐IR confirmed the creation of the composite structure of fibers. RT‐qPCR analysis showed that the expression of rhodopsin and peripherin genes in electrically stimulated cells were significantly higher (5.7‐ and 6.23‐fold, respectively; p ≤ 0.05) than those with no electrical stimulation. Collectively, it seems that the combination of PCL/PPY/MWCNTs scaffold, as a suitable conductive scaffold, and electrical stimulation could be an effective approach in the differentiation of stem cells in retinal tissue engineering.
关键词： electrical conductive,trabecular meshwork mesenchymal stem cells,photoreceptor‐like cells,nanostructure
更新于2025-11-14 15:18:02