scholarly journals The Influence of Dopant Concentration on Optical-Electrical Features of Quantum Dot-Sensitized Solar Cell

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2865
Author(s):  
Dang Huu Phuc ◽  
Ha Thanh Tung ◽  
Van-Cuong Nguyen ◽  
My Hanh Nguyen Thi
Keyword(s):  
Thin Films ◽  
Quantum Dot ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Photocurrent Density ◽  
Band Gap Energy ◽  
Electrochemical Impedance Spectrum ◽  
X Ray Diffraction ◽  
Electron Phonon Interaction ◽  
Optical Films

In this study, TiO2/CdS/CdxCu1−xSe, TiO2/CdS/CdxMn1−xSe, and TiO2/CdS/CdxAg2−2xSe thin films were synthesized by chemical bath deposition for the fabrication of photoanode in quantum-dot-sensitized solar cells. As a result, the structural properties of the thin films have been studied by X-ray diffraction, which confirmed the zinc Blende structure in the samples. The optical films were researched by their experimental absorption spectra with different doping concentrations. Those results were combined with the Tauc correlation to estimate the absorption density, the band gap energy, valence band and conduction band positions, steepness parameter, and electron–phonon interaction. Furthermore, the electrical features, electrochemical impedance spectrum and photocurrent density curves were carried out. The result was used to explain the enhancing performance efficiency.

scholarly journals Study on the Synthesize, Characterization, and Conductive Performance of Nickelzircomolybdnum Heteropoly Acid Salt with Keggin Structure

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Zhihong Zhang ◽  
Baoying Wang ◽  
Yijing Zhang ◽  
Gehong Zhang ◽  
Yujing Wang
Keyword(s):  
Conduction Mechanism ◽  
Heteropoly Acid ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Heteropoly Compound ◽  
Electrochemical Impedance Spectrum ◽  
Acid Salt ◽  
X Ray Diffraction ◽  
Protonic Conduction ◽  
X Ray

A novel heteropoly acid salt, Na6[Ni(Mo11ZrO39)]·20H2O, has been synthesized by the means of acidification and adding the reactants into the solution step by step. The heteropoly compound was characterized by elemental analysis, TGA/DSC, infrared spectrum, ultraviolet spectrum, X-ray diffraction, and SEM. Its protonic conduction was measured by the means of the electrochemical impedance spectrum. The results showed that it belongs to the Keggin type, and its conductivity value was 1.23 × 10–2 S/cm at 23°C when the relative humidity was 60%, and the conductivity enhanced with the elevated temperature. Its proton conduction mechanism was in accordance with vehicle mechanism, and the activation energy was 27.82 kJ/mol.

Fe-Doped UiO-66 Combined with ZnIn2S4 for Adsorption and Degradation of RhB Under Visible Light

NANO ◽  
2020 ◽  
Vol 15 (07) ◽  
pp. 2050089
Author(s):  
Litong Niu ◽  
Shaoping Hu ◽  
Yali Ma ◽  
Mingming Wang ◽  
Bolin Lv ◽  
...  
Keyword(s):  
Visible Light ◽  
Electrochemical Impedance ◽  
Diffuse Reflectance Spectroscopy ◽  
Photogenerated Electron ◽  
Impedance Spectrum ◽  
Solvothermal Reaction ◽  
Electrochemical Impedance Spectrum ◽  
X Ray Diffraction ◽  
One Pot ◽  
Ft Ir

Novel ZnIn2S4/FeUiO-66 (ZFeU) photocatalyst with different proportion of FeUiO-66 has been successfully prepared by a facile one-pot solvothermal reaction. The as-synthesized nanocomposites have been thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Brunauer–Emmett–Teller (BET) characterization, photoluminescence (PL) analysis and electrochemical impedance spectrum (EIS). The photocatalytic performance of ZFeU nanocomposites for the photodegradation of RhB under visible light irradiation was better than that of ZnIn2S4 and FeUiO-66 alone. The experiment results showed the 20% ZFeU nanocomposites had the best photocatalytic properties. At the same time, a probable mechanism was discussed and it was believed that introduction of FeUiO-66 on ZnIn2S4 would minimize the recombination of photogenerated electron-hole pairs, leading to the enhancement of the photocatalytic activity.

scholarly journals λ-MnO2 Thin Films with Sponge-Like Structures: Synthesis, Characterization and Physiochemical Applications

2021 ◽  
Vol 21 (5) ◽  
pp. 1187
Author(s):  
Khalid Abdelazez Mohamed Ahmed
Keyword(s):  
Thin Films ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Impedance Spectrum ◽  
Particle Growth ◽  
Crystal Form ◽  
Electrochemical Impedance Spectrum ◽  
Significant Research ◽  
Physicochemical Features ◽  
Adsorption Desorption

Manganese dioxide has acquired significant research attentiveness in many fields over the past years because of its exciting physicochemical features. The magnetized λ-MnO2 thin films with sponge-like structures (TSLs) were prepared by hydrothermal-soft chemical and delithiation-lithium manganese process. The XRD, XPS, EDX, FESEM, TEM, HR-TEM, and N2 adsorption-desorption techniques were used to characterize the as-prepared product’s structure composition, morphology, and surface area. The particle growth details of λ-MnO2 are postulated by the oxidation-ionic change-delithiation (OID) mechanism. The electrochemical property was analyzed by galvanostatic discharge-charging, electrochemical impedance spectrum (EIS), and cyclic voltammetry (CV). Special attention of λ-MnO2 S.L.s is given to their applications in the degradation of methyl orange (MO) from wastewater under O2 air bubble pump and cathodic substance in the lithium-ion battery. Due to the peculiarity crystal form and morphology face, the λ-MnO2 TSLs might be promisingly applied in the various physicochemical area.

Photoferroelectric Effects of Undoped and Extrinsic Ion-Doped PZT Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
Li Li ◽  
Chhiu-Tsu Lin ◽  
Martin S. Leung ◽  
Paul M. Adams ◽  
Russell A. Lipeles
Keyword(s):  
Thin Films ◽  
Optical Memory ◽  
Hysteresis Loops ◽  
Band Gap Energy ◽  
Acetate Solution ◽  
X Ray Diffraction ◽  
Pzt Thin Films ◽  
Photocurrent Spectroscopy ◽  
Visible Wavelengths ◽  
Mn Doped

ABSTRACTDeposition by aqueous acetate solution (DAAS) technique was used to synthesize undoped and 5 wt% Cr-, Mn-, Eu-, or Pr-doped Pb(Zr0.53Ti0.47O3 [PZT] thin films. The dopant was incorporated into PZT either in the precursor coating solution or via thermal diffusion into undoped PZT. X-ray diffraction shows that ion-doped PZT thin films on Pt<l 1 l>/Ti/SiO2/Si<100> (in particular, the Mn- and Eu- doped samples) display better crystallinity and smaller lattice parameters than those on sapphire substrates. The enhancement of photoconductivity at visible wavelengths measured by excitation photocurrent spectroscopy (EPS) goes as Cr-doped∼Mn-doped > Eu-doped ∼ Pr-doped. Only Mn-doped PZT perovskites have the band gap energy red-shifted to 360 nm from 330 nm. The space charge (or photovoltaic) field was estimated to be < 8 v when about 100 v was applied to ion-doped PZT thin films with 260 or 320 nm light. By using laser irradiation at selected wavelengths and switching the polarity of applied bias voltage, the expected changes in resistance (Ry) and remanent polarization (±Pr) states were observed in the P-E hysteresis loops. The possible applications of extrinsic ion-doped PZT thin films in optical memory devices are discussed.

Preparation of Cu2ZnSnS4 Thin Films by Successive Ionic Layer Adsorption and Reaction (SILAR) Method for Supercapacitor Applications

2020 ◽  
Vol 20 (10) ◽  
pp. 6235-6244 ◽  
Author(s):  
A. Murugan ◽  
V. Siva ◽  
A. Shameem ◽  
S. Asath Bahadur
Keyword(s):  
Thin Films ◽  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Silar Method ◽  
Layer Adsorption ◽  
Diffraction Patterns ◽  
Czts Thin Films ◽  
Supercapacitor Applications ◽  
Ionic Layer

The Cu2ZnSnS4 (CZTS) thin films have been prepared at different deposition cycles, deposited on a glass substrate by successive ionic layer adsorption and reaction (SILAR) method followed by the annealing process at elevated temperature. The investigations on the films have been carried out to understand and confirm its structure, functional group present, crystalline morphology, optical and electrochemical behavior. The powder X-ray diffraction patterns recorded indicate that the deposited films are formed in the tetragonal structure. Other parameters like grain size, dislocation density, and microstrain are also calculated. The uniform surface of the films with spherical shaped morphology has been observed by Scanning Electron Microscopy, and the elemental compositions have been confirmed by EDAX. Electrochemical behavior such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge analysis have been carried out by electrochemical workstation. The modified electrode exhibits maximum specific capacitance value as 416 F/g for a pure sample. Optical studies have shown that the band gaps are estimated between 1.40 eV and 1.57 eV.

Effect of Solution Concentration in the Optical and Structural Properties of ZnO Thin Films

2018 ◽  
Vol 18 ◽  
pp. 113-117 ◽  
Author(s):  
Abdelkader Hafdallah ◽  
Aimane Guedri ◽  
Mohamed Salah Aida ◽  
Nadhir Attaf
Keyword(s):  
Thin Films ◽  
Solution Concentration ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Glass Substrates ◽  
Optical Band Gaps ◽  
Optical Films ◽  
Spray Technique ◽  
Uv Visible

In the present work we prepared conducting and transparent thin films ZnO with different solution concentrations by pyrolysis spray technique on glass substrates. These films are obtained starting from solution of zinc acetate dehydrate [Zn(CH3COO)2.2H2O] dissolved in methanol, at substrate temperature fixed T =350°C with a concentration of solution vary from 0.05-0.2 M. Our interest is on the investigation of solution concentration on the structural and optical properties of these films. The X-ray diffraction (XRD) results showed that the synthesized ZnO films are polycrystalline with preferred orientation along the (002) plane. The optical films characterization was carried out by the UV-Visible transmission. The optical gap and films disorder were deduced from the absorption spectra, The values of optical band gaps vary between 3.24 and 3.43 eV.

EIS Study of Corrosion Behavior of Hot-Dip Galvanized Steel in 5% NaCl Aqueous Solution

2011 ◽  
Vol 335-336 ◽  
pp. 779-782
Author(s):  
Shi Quan He ◽  
Hui Zhong
Keyword(s):  
Aqueous Solution ◽  
Equivalent Circuit ◽  
Corrosion Behavior ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Impedance Spectrum ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Electrochemical Impedance Spectrum

Corrosion behaviour of hot-dip galvanized steel in 5% NaCl aqueous solution was studied by electrochemical impedance spectrum (EIS) technique. The results revealed that corrosion behaviour of hot-dip galvanized steel has a great relationship with immersion time. With the increase of immersion time, corrosion products are constantly changing, and the impedance of corrosion products are different. Parameters fitted by equivalent circuit show that the impedance of corrosion products increased at first, then decreased.

Properties of CdS Thin Films Grown by Chemical Bath Deposition as a Function of Bath Temperature

2009 ◽  
Vol 609 ◽  
pp. 243-247 ◽  
Author(s):  
H. Moualkia ◽  
S. Hariech ◽  
M.S. Aida
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Chemical Bath Deposition ◽  
Bath Temperature ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Cds Thin Films ◽  
Direct Band

The present work deals with the preparation and characterization of cadmium sulfur (CdS) thin films. These films are prepared by chemical bath deposition on the well cleaned glass substrates. The thickness of the samples was measured by using profilometer DEKTAK, structural and optical properties were studied by X-ray diffraction analysis, and UV-visible spectrophotometry. The optical properties of the films have been investigated as a function of temperature. The band gap energy and Urbach energy were also investigated as a function of temperature. From the transmittance data analysis the direct band gap ranges from 2.21 eV to 2.34 eV. A dependence of band gap on temperature has been observed and the possible raisons are discussed. Transmission spectra indicates a high transmission coefficient (75 %). Structural analysis revealed that the films showed cubic structure, and the crystallite size decreased at a higher deposition temperature.

Quantitative Rapid Analysis Method for Ofloxacin in Raw Milk Based on Molecule-Specific Recognition and Electrochemical Impedance Spectrum

2017 ◽  
Vol 60 (5) ◽  
pp. 1439-1443 ◽  
Author(s):  
Guohua Hui ◽  
Yibin Ying
Keyword(s):  
Quantitative Analysis ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Raw Milk ◽  
Rapid Analysis ◽  
Electrochemical Impedance Spectrum ◽  
Analysis Method ◽  
Eigen Values ◽  
Sodium Tetraphenylboron ◽  
Association Complex

Abstract. A quantitative rapid analysis method for ofloxacin detection in raw milk using molecule-specific recognition and an electrochemical impedance spectrum (EIS) technique was investigated in this study. An association complex (AC) formed by a combination of ofloxacin and sodium tetraphenylboron (ST) was used as the active material for electrochemical analysis. A carbon screen-printed electrode (CSE) was modified with the AC to form an electrochemical active membrane for ofloxacin detection. EIS data of pretreated raw milk samples were measured and analyzed with a non-linear bistable stochastic resonance (SR) model. Trace ofloxacin concentrations were characterized by SR output signal-to-noise ratio (SNR) eigen values. An ofloxacin quantitative analysis model was built based on SNR eigen values. Experimental results demonstrated that the proposed method presented good accuracy, repeatability, and recovery. It is a promising way for ofloxacin detection in raw milk. Keywords: Association complex, Electrochemical impedance spectrum, Ofloxacin, Quantitative analysis, Sodium tetraphenylboron.

scholarly journals Composition and Performance of Nanostructured Zirconium Titanium Conversion Coating on Aluminum-Magnesium Alloys

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sheng-xue Yu ◽  
Rui-jun Zhang ◽  
Yong-fu Tang ◽  
Yan-ling Ma ◽  
Wen-chao Du
Keyword(s):  
Corrosion Resistance ◽  
Salt Solution ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Conversion Coating ◽  
Mg Alloy ◽  
Electrochemical Impedance Spectrum ◽  
X Ray ◽  
Titanium Salt

Nanostructured conversion coating of Al-Mg alloy was obtained via the surface treatment with zirconium titanium salt solution at 25°C for 10 min. The zirconium titanium salt solution is composed of tannic acid 1.00 g·L−1, K2ZrF60.75 g·L−1, NaF 1.25 g·L−1, MgSO41.0 g/L, and tetra-n-butyl titanate (TBT) 0.08 g·L−1. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrum (FT-IR) were used to characterize the composition and structure of the obtained conversion coating. The morphology of the conversion coating was obtained by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results exhibit that the zirconium titanium salt conversion coating of Al-Mg alloy contains Ti, Zr, Al, F, O, Mg, C, Na, and so on. The conversion coating with nm level thickness is smooth, uniform, and compact. Corrosion resistance of conversion coating was evaluated in the 3.5 wt.% NaCl electrolyte through polarization curves and electrochemical impedance spectrum (EIS). Self-corrosion current density on the nanostructured conversion coating of Al-Mg alloy is9.7×10-8A·cm-2, which is only 2% of that on the untreated aluminum-magnesium alloy. This result indicates that the corrosion resistance of the conversion coating is improved markedly after chemical conversion treatment.

Sign in / Sign up

Export Citation Format

Share Document