Transparent Conductive Glass Research Articles

Hybrid electrochromic film based on polyaniline and TiO2 nanorods array

Titanium dioxide (TiO2) nanorods (NRs) array was successfully prepared via hydrothermal method on fluorine doped tinoxide (FTO) coated transparent conductive glass substrate. The hybrid film of polyaniline (PANI)/TiO2 NRs was achieved through electrochemical polymerization of aniline onto the TiO2 NRs array film. The electrochromic and optical properties of the hybrid film were investigated by cyclic voltammetry (CV), amperometric i–t and UV–vis spectroscopy. The results indicate that the hybrid film has long term stability and reversible color changes after cyclic voltammetry scans for 200circles. The PANI/TiO2 NRs hybrid film can show three different colors. Response time of PANI/TiO2 NRs hybrid film is about 0.7s and 2.6s at different states, respectively. The TiO2 NRs array and the loose, porous surface among the hybrid film facilitate charge transmission and also provide large surface area for electrochemical reaction.

Enhanced Photoelectrocatalytic Activity of Oriented Rutile TiO<sub>2</sub> Nanorod Array Film through Nb Doping

TiO2 nanorod array films with or without Nb doping grown directly on transparent conductive glass (FTO) were prepared by a facile hydrothermal method. The films were characterized by means of field emission scanning electron microscopy (FE-SEM) with energy-dispersive x-ray spectra (EDS), X-ray diffraction (XRD) and the X-ray photoelectron spectroscoy (XPS). The electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV) and transient photocurrent were investigated in a three-electrode system with TiO2 nanorod array film served as the photoanode. The photoelectrocatalytic activity of the films was evaluated by the oxidation of glucose under UV irradiation. The results show that both the pure and Nb-doped TiO2 nanorods perpendicularly grown on FTO substrate are rutile phase. The resistance of the TiO2 nanorod array photoanode is decreased significantly by Nb doping. The steady-state photocurrent (iss) for glucose oxidation at Nb-doped TiO2 nanorod array film is much higher than that at the pure one. The enhanced photoelectrocatalytic activity of the Nb-doped TiO2 nanorods could be attributed to the enhanced charge transport ability.

Study on the thermal stability of Ga-doped ZnO thin film: A transparent conductive layer for dye-sensitized TiO2 nanoparticles based solar cells

Generally, optoelectronic devices are fabricated at a high temperature. So the stability of properties for transparent conductive oxide (TCO) films at such a high temperature must be excellent. In the paper, we investigated the thermal stability of Ga-doped ZnO (GZO) transparent conductive films which were heated in air at a high temperature up to 500°C for 30min. After heating in air at 500°C for 30min, the lowest sheet resistance value for the GZO film grown at 300°C increased from 5.5Ω/sq to 8.3Ω/sq, which is lower than 10Ω/sq. The average transmittance in the visible light of all the GZO films is over 90%, and the highest transmittance is as high as 96%, which is not influenced by heating. However, the transmittance in the near-infrared (NIR) region for the GZO film grown at 350°C increases significantly after heating. And the grain size of the GZO film grown at 350°C after annealing at 500°C for 30min is the biggest. Then dye-sensitized TiO2 NPs based solar cells were fabricated on the GZO film grown at 350°C (which exhibits the highest transmittance in NIR region after heating at 500°C for 30min) and 300°C (which exhibits the lowest sheet resistance after heating at 500°C for 30min). The dye-sensitized solar cell (DSSC) fabricated on the GZO film grown at 350°C exhibits superior conversion efficiency. Therefore, transparent conductive glass applying in DSSCs must have a low sheet resistance, a high transmittance in the ultraviolet–visible–infrared region and an excellent surface microstructure.

Fabrication of TiO2 nano-branched arrays/Cu2S composite structure and its photoelectric performance

Hierarchical nanostructured TiO2 is known to be ideal materials for photoelectrochemical water splitting because of its excellent light harvesting efficiency, efficient charge separation and transport properties. In the present work, rutile TiO2 nano-branched arrays (NBs) were grown directly on transparent conductive glass (FTO) using a simple two-step hydrothermal method. TiO2 NBs/Cu2S composite structure was subsequently synthesized through successive ionic layer adsorption and reaction (SILAR). Detailed growth mechanisms for TiO2 NBs nanostructure and TiO2 NBs/Cu2S composite structure were discussed. The optical property of composite structures was characterized, and enhanced absorption spectrum was discovered. A much higher hydrogen generation efficiency of 13.15% at 0.70V versus Ag/AgCl electrode was achieved for this TiO2 NBs/Cu2S composite structure. This is attributed to the improved light absorption and appropriate energy gap structure, which is over 40% higher than that of TiO2 NWs/Cu2S composite structure.

Conductive carbon paint as an anode buffer layer in inverted CdS/Poly(3-hexylthiophene) solar cells

Hybrid solar cells have been prepared by deposition of thin films of cadmium sulfide (CdS) on transparent conductive glass substrates, followed by the formation of poly(3-hexylthiophene) (P3HT) coatings. Conductive carbon paint (CP) layer was applied on top of P3HT before the evaporation of gold (Au) as metal contact. When the P3HT film thickness (d) was smaller than 600nm, photovoltaic (PV) performance of the CdS/P3HT solar cells was enhanced with CP layer. In the case of d=305nm, the presence of CP layer increased the open-circuit voltage (Voc) from 335 to 710mV and the short-circuit current density (Jsc) from 1.23 to 1.42mA/cm2 as well. The analysis of current–voltage (I–V) curves in the dark of the same type of cells indicates that CP reduced the leakage current and metal contact resistance, and increased the rectification ratio. I–V curves of hole-only Metal-1/P3HT/Metal-2 devices suggest that the presence of CP facilitates hole-extraction from P3HT. The comparison of charge recombination times at CdS/P3HT interface suggests that without CP layer, Au atoms could reach areas near the interface and facilitates charge recombination process. It is concluded that conductive carbon not only improves the ohmic contact between P3HT and top metal but also impedes the diffusion of the evaporated metal atoms deep inside the polymer films. This leads to better PV performance of the CdS/P3HT solar cells.

Low-temperature self-assembled vertically aligned carbon nanofibers as counter-electrode material for dye-sensitized solar cells

Low-temperature AC–DC PECVD is employed for direct growth of vertically aligned carbon nanofibers (VACNFs) on ordinary transparent conductive glass as counter-electrode material for dye-sensitized solar cells (DSSCs). To the best of our knowledge, this is the first report on utilization of VACNFs grown directly on ordinary FTO-coated glass as a cost-effective catalyst material in DSSCs. According to the FESEM images, the as-grown arrays are well aligned and dense, and offer uniform coverage on the surface of the substrate. In-plane and out-of-plane conductivity measurements reveal their good electrical conductivity, and Raman spectroscopy suggests a high number of electrocatalytic active sites, favoring charge transport at the electrolyte/electrode interface. Hybrid VACNF/Pt electrodes are also fabricated for performance comparison with Pt and VACNF electrodes. X-ray diffraction results verify the crystallization of Pt in hybrid electrodes and further confirm the vertical alignment of carbon nanofibers. Electrochemical characterization indicates that VACNFs provide both high catalytic and good charge transfer capability, which can be attributed to their high surface area, defect-rich and one-dimensional structure, vertical alignment and low contact resistance. As a result, VACNF cells can achieve a comparable performance (∼5.6%) to that of the reference Pt cells (∼6.5%). Moreover, by combination of the excellent charge transport and catalytic ability of VACNFs and the high conductivity of Pt nanoparticles, hybrid VACNF/Pt cells can deliver a performance superior to that of the Pt cells (∼7.2%), despite having a much smaller amount of Pt loading, which raises hopes for low-cost large-scale production of DSSCs in the future.

Preparation of porous glass films using phase separation phenomenon and growth behavior of phase-separated structure

We report the preparation of porous glass films on transparent conductive oxide-coated glass substrates using the phase separation phenomena and the growth behavior of the phase-separated structure. We confirmed that the etched glass films are composed of microscale pores, a three-dimensional porous framework of SiO2-rich phase with widths of about 40–300 nm, and a thin surface layer of about 40–90 nm thick. The SiO2-rich phase grew by diffusion-dominated growth and then viscous flow-dominated growth.

Self-aligned carbon nanotubes yarns (CNY) with efficient optoelectronic interface for microyarn shaped 3D photovoltaic cells

An innovative solid state dye sensitized photovoltaic carbon nanotubes yarn (DSP-CNY) has been developed using thermally-stable and highly conductive carbon nanotubes (CNT) yarns (CNYs). These CNYs are highly inter-aligned, ultrastrong and flexible with excellent electrical conductivity, mechanical integrity and catalytic properties. The CNYs are coated with a dye-incorporated TiO2 microfilm and intertwined with a second set of CNYs as a counter electrode (CE). The DSP-CNYs were developed without using any metal wires or any expensive transparent conductive oxides (TCOs), liquid electrolytes, or glass or plastic cladding. The maximum photon to current conversion efficiency (ηAM 1.5) achieved with prolonged-time stability was 2.57%. The yarn-shaped flexible cells were able to transport photocurrent over a significant distance using a simple cell configuration with a wide range of structural flexibility (30–330°). These cells are capable of efficiently harvesting incident photons regardless of direction and generating photocurrents with high efficiency and long term stability.

High-Performance Nanocomposite Based Memristor with Controlled Quantum Dots as Charge Traps

We report a novel approach to improve the resistive switching performance of semiconductor nanorod (NR) arrays, by introducing ceria (CeO2) quantum dots (QDs) as surface charge trappers. The vertically aligned zinc oxide (ZnO) (NR) arrays were grown on transparent conductive glass by electrochemical deposition while CeO2 QDs were prepared by a solvothermal method. Subsequently, the as-prepared CeO2 QDs were embedded into a ZnO NR array by dip coating to obtain a CeO2-ZnO nanocomposite. Interestingly, such a device exhibits excellent resistive switching properties with much higher ON/OFF ratios, better uniformity, and stability over the pure ZnO and CeO2 nanostructures. The origin of resistive switching was studied and the role of heterointerface was discussed.

Hydrothermal Fabrication of Hierarchically Anatase TiO2 Nanowire arrays on FTO Glass for Dye-sensitized Solar Cells

Hierarchical anatase TiO2 nano-architecture arrays consisting of long TiO2 nanowire trunk and numerous short TiO2 nanorod branches on transparent conductive fluorine-doped tin oxide glass are successfully synthesized for the first time through a facile one-step hydrothermal route without any surfactant and template. Dye-sensitized solar cells based on the hierarchical anatase TiO2 nano-architecture array photoelectrode of 18 μm in length shows a power conversion efficiency of 7.34% because of its higher specific surface area for adsorbing more dye molecules and superior light scattering capacity for boosting the light-harvesting efficiency. The present photovoltaic performance is the highest value for the reported TiO2 nanowires array photoelectrode.

Preparation and Characterization of SnO2 Thin Film Coating using rf-Plasma Enhanced Reactive Thermal Evaporation

Abstract Due to high transparency and electrical conductivity, the transparent conductive glass applied in very large area like gas sensor, LCD, image storage device. It is also use in field of solar cell for both Si solar cell and Dye sensitized solar cell. Radio Frequency Plasma enhanced Reactive Thermal Evaporation method is used to fabricate the transparent conductive glass by coating of tin oxide on transparent glass. In this study on attempt has been made for SnO2 thin film coating using rf-PERTE with variation of oxygen partial pressure of 8×10 -4 mbar, 6×10 -4 mbar, 4×10 -4 mbar, with tin oxide boat voltage of 16 V, 20 V, 24 V and deposition time of tin oxide on the glass subtract 3 min, 10 min, 20 min and compare resistivity with commercial available ITO. The resistivity observed for thin film coated on lab and commercially available Indium coated ITO were 82.63/cm 2 and 1.191/cm 2 respectively.

Reduced impurity-driven defect states in anodized nanoporous Nb2O5: the possibility of improving performance of photoanodes

Anodized nanoporous Nb2O5 films are synthesized using two different types of electrolyte compositions onto transparent conductive glasses and their impurities induced during the anodization process are assessed. These films are incorporated as photoanodes in dye sensitized solar cells (DSSCs). The one with no traces of impurity-driven defects exhibits higher current density and longer electron lifetimes, and consequently, an improvement in photoconversion efficiencies compared to the one that contains impurities.

A poly(3-hexylthiophene) modified CdS@TiO2shell-core nanorod array solar cell

In this paper, a novel solar cell device was fabricated based on poly(3-hexylthiophene) (P3HT) modified CdS@TiO2 shell-core nanorod array as the photoanode. To prepare the photoanode, rutile TiO2 nanorod arrays were first grown directly on fluorine doped transparent conductive glass (FTO) by a simple hydrothermal method. Then the CdS nanoparticles and a thin layer of P3HT were deposited onto the surface of the TiO2 nanorods sequentially through an electrochemical route. It was demonstrated that the surface modification of the TiO2 nanorods with CdS nanoparticles and P3HT could enhance the light absorption in the visible region. An energy conversion efficiency up to 1.38% was obtained with the designed solar cell.

One-Step Electrophoretic Deposition of Magnesium Oxide-Coated Tin Oxide Film and Its Application to Flexible Dye Sensitized Solar Cells

Magnesium oxide-coated tin oxide (MgO-coated SnO2) powder consisted of aggregates was prepared by a facile method. The MgO-coated SnO2 powder was characterized by X-ray diffractometer, field emission scanning electron microscope, energy dispersive spectroscopy and Raman spectroscopy. The aggregates were composed of nanoparticles, which promised a large surface area of 74.27 m2 g−1. MgO-coated SnO2 porous films utilized in dye-sensitized solar cells (DSSCs) were prepared using one-step electrophoretic deposition (EPD) method. The as-deposited films showed no cracks when the film thickness was 49.9 μm. The deposited films are hydrolysed at 413 K and irradiated under UV light. The post-treated MgO/SnO2 films are used as flexible photoanodes in dye-sensitized solar cells (DSSCs). Electrochemical impedance spectroscopy (EIS) is employed to quantify the electron lifetime (τe) of the MgO/SnO2 films. The amount of MgO coating and film thickness are optimized to achieve high energy conversion efficiency. The optimized MgO/SnO2 photoanodes based on transparent conductive glass substrates show an excellent photovoltaic response, with overall power conversion efficiency reaching 5.48% under AM 1.5 G illumination (100 mW cm−2), having a short circuit current density, open circuit voltage, and fill factor of 11.48 mA cm−2, 0.656 V and 0.73, respectively. All-plastic DSSCs are also assembled, which show a light-to-electricity conversion efficiency of 4.01%.

Effect of KOH treatment on structural and photovoltaic properties of ZnO nanorod arrays

ZnO nanorod arrays (NRs) were synthesized on the fluorine-doped SnO2 transparent conductive glass (FTO) by a simple chemical bath deposition (CBD) method combined with alkali-etched method in potassium hydroxide (KOH) solution. X-ray diffraction (XRD), scanning electron microscopy (SEM) and current—voltage (I—V) curve were used to characterize the structure, morphologies and optoelectronic properties. The results demonstrated that ZnO NRs had wurtzite structures, the morphologies and photovoltaic properties of ZnO NRs were closely related to the concentration of KOH and etching time, well-aligned and uniformly distributed ZnO NRs were obtained after etching with 0.1 mol/L KOH for 1 h. ZnO NRs treated by KOH had been proved to have superior photovoltaic properties compared with high density ZnO NRs. When using ZnO NRs etched with 0.1 mol/L KOH for 1 h as the anode of solar cell, the conversion efficiency, short circuit current and open circuit voltage, compared with the unetched ZnO NRs, increased by 0.71%, 2.79 mA and 0.03 V, respectively.

Solid state dye-sensitized photovoltaic micro-wires (DSPMs) with carbon nanotubes yarns as counter electrode: Synthesis and characterization

Innovative all solid state dye-sensitized photovoltaic micro-wires (DSPMs) have been developed using low-cost, thermally-stable and highly conductive titanium micro-wires and carbon nanotubes yarns (CNYs). Highly inter-aligned, ultrastrong and flexible CNYs with excellent electrical conductivity, mechanical integrity and catalytic property have been successfully used as counter electrodes (CEs). The open circuit voltage and current density of the DSPMs can remarkably be improved through optimizing the numbers of CNYs and CNYs–TiO2 interface. Optimizing the number of CNYs in the CEs yields a photoconversion efficiency of 0.1959% with prolonged-time stability. The DSPMs were made without expensive transparent conductive oxides (TCOs), liquid electrolytes and glass or plastic cladding. The DSPMs are able to transport photocurrent over a significant distance using a simple cell configuration with a wide range of flexibility (10–180°). These cells are capable of efficiently harvesting incident photon from any direction and generate photocurrent with an efficient reproducibility throughout a large number of illumination on–off cycles.

Hydrothermally Processed TiO2 Nanowire Electrodes with Antireflective and Electrochromic Properties

Dual functionalities of antireflective and electrochromic properties-based anatase TiO(2) nanowire devices with a high-porosity cross-linked geometry directly grown onto transparent conductive glass was achieved for the first time through a simple one-step hydrothermal process under mild alkali conditions. Devices fashioned from these TiO(2) nanowires were found to display enhanced optical transparency in the visible range, better color contrast, and faster color-switching time in comparison to devices made from nanoparticles. These improvements can be attributed to the low refractive index and high porosity of the TiO(2) nanowires and their larger accessible surface area for Li(+) intercalation and deintercalation, leading to enhanced capabilities for transparent electrochromic smart windows.

A two-step route to synthesize highly oriented ZnO nanotube arrays

Large-scale and highly oriented ZnO nanotube arrays are synthesized on transparent conductive glass substrates by a two-step route. First, ZnO nanorod arrays were prepared by electrochemical deposition from an aqueous solution of zinc nitrate. Then, hollow ZnO nanotubes were obtained by the selective dissolution of the electrodeposited ZnO nanorods in potassium hydroxide solution. Field emission scanning electron microscopy (FESEM) and X-ray powder diffraction (XRD) have been used to characterize the morphology and structure of the derived products. The effect of the concentration of alkali, dissolution time, and temperature on the formation process and morphologies of ZnO nanotube arrays has been discussed.

Cellulose acetate fibers covered by CdS nanoparticles for hybrid solar cell applications

Abstract In this work cellulose acetate (CA) fibers with a diameter of approximately 1 μm were immersed in a cadmium sulfide (CdS) precursor solution. After 3 h the original white color CA fibers became yellow and maintained the same form, suggesting the deposition of CdS on fiber surface. SEM images showed that CA fibers were covered by uniformly sized CdS nanoparticles of approximately 100 nm. XRD and optical absorption spectra indicated that they contained mostly cubic crystalline phase with the optical band gap of 2.43 eV. CdS coated CA fibers, called CdS(CA) fibers, were dispersed in a polar dispersant (dimethyl sulfoxide, DMSO) and then mixed with a poly(3-hexylthiophene) (P3HT) solution in a non-polar solvent (dichlorobenzene, DCB). The mixture was cast onto a transparent conductive glass substrate (Indium–Tin–Oxide, ITO), and after solvent evaporation a thin layer of CdS(CA)–P3HT composite was formed. It is observed that the volume relation between the polar dispersant and non-polar solvent influences the solubility of the P3HT product in the composite coating and the photovoltaic performance of the corresponding cell as well. The mass ratio between CdS(CA) fibers and P3HT in the composite layer affects the optical absorption of the composite. The best photovoltaic performance was obtained in CdS(CA)–P3HT based cells with a volume relation between DCB and DMSO of 3.5–1, a mass ratio between CdS(CA) and P3HT of 1:1, and a rapid drying process for composite coatings.

Comparison of carbon nanotube modified electrodes for photovoltaic devices

Substrates with four different nanotube modifications have been prepared and their electron transport properties measured. Two modification techniques were compared; covalent chemical attachment of both single and multi-walled carbon nanotubes to transparent conductive (fluorine doped tin oxide) glass surfaces and chemical vapour deposition (CVD) growth of both single and multi-walled carbon nanotubes on highly doped conductive silicon wafers. These carbon nanotube modified substrates were investigated using scanning electron microscopy and substrates with nanotubes grown via CVD have a much higher density of nanotubes than substrates prepared using chemical attachment. Raman spectroscopy was used to verify that nanotube growth or attachment was successful. The covalent chemical attachment of nanotubes was found to increase substrate electron transfer substantially compared to that observed for the bare substrate. Nanotube growth also enhanced substrate conductivity but the effect is smaller than that observed for covalent attachment, despite a lower nanotube density in the attachment case. In both modification techniques, attachment and growth, single-walled carbon nanotubes were found to have superior electron transfer properties. Finally, solar cells were constructed from the nanotube modified substrates and the photoresponse from the different substrates was compared showing that chemically attached single-walled nanotubes led to the highest power generation.