Indium Tin Oxide-coated Polyethylene Naphthalate Research Articles

Well-Dispersive Polypyrrole and MoSe2 Embedded in Multiwalled Carbon Nanotube@Reduced Graphene Oxide Nanoribbon Electrocatalysts as the Efficient Counter Electrodes in Rigid and Plastic Dye-Sensitized Solar Cells

In this study, a core–shell structured multiwall carbon nanotube@reduced graphene oxide nanoribbon (MWCNT@rGNR) was prepared by the facile unzipping of MWCNTs with mild conditions to synthesize the composites of the MWCNT@rGNR and polypyrrole (PPy) or MoSe2, which were used as the electrocatalysts for the counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). The transmission electron microscopy image of the MWCNT@rGNR showed a graphene sheet structure found on both sides of the MWCNTs, indicating a central core of the MWCNTs and its shell of the rGNR. The obtained MWCNT@rGNR functionalized with PPy or MoSe2 was envisaged to have the advantages of both component, that are the unique electronic structure of the MWCNT@rGNR and the synergistic effects of conductive PPy or electrocatalytically active MoSe2, respectively. The DSSCs with PPy/MWCNT@rGNR0.3 and MoSe2/MWCNT@rGNR0.3 showed comparable efficiency (photoelectric conversion efficiency, PCE = 7.48 and 8.34%, respectively), short-circuit current (Isc = 17.97 and 17.11 mA cm–2, respectively), and open-circuit voltage (Voc = 0.80 and 0.84 V, respectively) without any loss of the fill factor (FF = 0.52 and 0.58, respectively) as compared to the cell fabricated using a standard Pt electrode. The PCE of a standard Pt CE was 7.70% with an Isc of 16.09 mA cm–2, Voc of 0.76 V, and FF of 0.63. According to the results of the electrochemical measurements, composites with PPy or MoSe2 showed better electrocatalytic activity, higher redox-active surface area, and extremely large heterogeneous electron transfer rate constant. The plastic devices assembled with the PPy/MWCNT@rGNR0.3 and MoSe2/MWCNT@rGNR0.3 coated on a flexible plastic substrate (indium tin oxide-coated polyethylene naphthalate; ITO/PEN)exhibited impressive PCEs of 4.61 and 5.25%, respectively, comparable to those coated on the rigid fluorine-doped tin oxide glass substrate. This work presented a facile low-temperature method to fabricate high-performance MWCNT@rGNR composite-based CEs to make them applicable to large-scale plastic DSSCs.

An efficient, flexible perovskite solar module exceeding 8% prepared with an ultrafast PbI2 deposition rate

Large-area, pinhole-free CH3NH3PbI3 perovskite thin films were successfully fabricated on 5 cm × 5 cm flexible indium tin oxide coated polyethylene naphthalate (ITO-PEN) substrates through a sequential evaporation/spin-coating deposition method in this research. The influence of the rate-controlled evaporation of PbI2 films on the quality of the perovskite layer and the final performance of the planar-structured perovskite solar cells were investigated. An ultrafast evaporation rate of 20 Å s−1 was found to be most beneficial for the conversion of PbI2 to CH3NH3PbI3 perovskite. Based on this high-quality CH3NH3PbI3 film, a resultant flexible perovskite solar sub-module (active area of 16 cm2) with a power conversion efficiency of more than 8% and a 1.2 cm2 flexible perovskite solar cell with a power conversion efficiency of 12.7% were obtained.

Solvent-assisted microstructural evolution and enhanced performance of porous ZnO films for plastic dye-sensitized solar cells

Abstract A low-temperature process for fabricating porous ZnO films on plastic, indium tin oxide-coated polyethylene naphthalate substrates is developed for their use in dye-sensitized solar cells. A special attention is paid to modification of microscopic morphologies for enhancing interparticle connection. ZnO films having two kinds of macroscopic morphologies (flower-like particles and densely packed nanoparticles) are fabricated at temperatures below the heatproof temperature of the substrate, and subsequently immersed in mixed solvents composed of water and ethanol at 90 °C. The immersion leads to the growth of constituting ZnO particles and also the evolution of interparticle connection, depending on solvent compositions. The cell performance is largely improved especially in a short-circuit current density and a power conversion efficiency. The immersion effect is more remarkable for the cell using the densely packed ZnO film, with a 62% increase in the current density and an 84% increase in the conversion efficiency. In consequence, our plastic N719-sensitized ZnO cell shows the conversion efficiency as high as 4.1%.

Fabrication of layered hydroxide zinc nitrate films and their conversion to ZnO nanosheet assemblies for use in dye-sensitized solar cells

Layered hydroxide zinc nitrate (LHZN; Zn5(NO3)2(OH)8·xH2O) films were fabricated on glass or plastic substrates by a chemical bath deposition method combined with a homogeneous precipitation in methanolic solutions. High- or low-temperature pyrolytic decomposition of the LHZN films having two-dimensional morphology was attempted to obtain porous ZnO nanosheet-assembly films. The LHZN films were converted into porous ZnO films by pyrolyzing at temperatures above 400 °C, while porous LHZN/ZnO hybrid films were obtained by pyrolyzing at a lower temperature of 120 °C without morphological changes. The pyrolyzed ZnO films were applied to dye-sensitized solar cells (DSSCs), resulting in the generation of relatively high open-circuit voltages. The low-temperature pyrolysis enabled us to fabricate the LHZN/ZnO film even on the plastic substrate. Actually a cell using the LHZN/ZnO film on an indium tin oxide-coated polyethylene naphthalate substrate showed an energy conversion efficiency of 2.08% with a high open-circuit voltage around 0.70 V.

Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3.

Transparent and flexible capacitors based on nanolaminate Al2O3/TiO2/Al2O3 dielectrics have been fabricated on indium tin oxide-coated polyethylene naphthalate substrates by atomic layer deposition. A capacitance density of 7.8 fF/μm2 at 10 KHz was obtained, corresponding to a dielectric constant of 26.3. Moreover, a low leakage current density of 3.9 × 10−8 A/cm2 at 1 V has been realized. Bending test shows that the capacitors have better performances in concave conditions than in convex conditions. The capacitors exhibit an average optical transmittance of about 70% in visible range and thus open the door for applications in transparent and flexible integrated circuits.

Fabrication of Nanostructured Zinc Oxide Films on Plastic Substrates by Pyrolysis Method and their Application to Dye-Sensitized Solar Cells

t has been attempted to utilize plastic substrates for electrodes, instead of conventional glass substrates, to fabricate flexible, lightweight, and low-cost dye-sensitized solar cells (DSSCs). We examined a pyrolysis method by which preformed layered hydroxide zinc acetate (LHZA: Zn5(OH)8(CH3COO)2·2H2O) films were converted into ZnO films at temperatures below 120 oC. Since the pyrolyzed films still contained zinc acetate compounds, they were immersed in hot water aiming at removing such the impurities. This hot water treatment influenced the film morphology to a large extent. The energy conversion efficiency of 3.41% was obtained for the cell using an N719/ZnO electrode fabricated on an indium tin oxide-coated polyethylene naphthalate (ITO-PEN) substrate through the present pyrolysis method.

High-Performance Plastic Platinized Counter Electrode via Photoplatinization Technique for Flexible Dye-Sensitized Solar Cells

A photoplatinization technique was proposed to deposit Pt on a thin TiO(2) layer modified indium tin oxide-coated polyethylene naphthalate (ITO/PEN) substrate at low temperature (about 50 °C after 1 h of UV irradiation) for the first time. The fabrication process includes coating and hydrolyzing the tetra-n-butyl titanate to form a TiO(2)-modified layer and the photoplatinization of the modified substrate in H(2)PtCl(6)/2-propanol precursor solution under UV irradiation. The obtained platinized electrodes were used as counter electrodes (CE) for flexible dye-sensitized solar cells (FDSCs). The well-optimized platinized electrode showed high optical transmittance, up to 76.5% between 400 and 800 nm (T(av)), and the charge transfer resistance (R(ct)) was as low as 0.66 Ω cm(2). A series of characterizations also demonstrated the outstanding chemical/electrochemical durability and mechanical stability of the platinized electrode. The FDSCs with TiO(2)/Ti photoanodes and the obtained CEs achieved a power conversion efficiency (PCE) up to 8.12% under rear-side irradiation (AM 1.5 illumination, 100 mW cm(-2)). The obtained CEs were also employed in all-plastic bifacial DSCs. When irradiated from the rear side, the bifacial FDSC yielded a PCE of 6.26%, which approached 90% that of front-side irradiation (6.97%). Our study revealed that, apart from serving as a functional layer for deposition of Pt, the thin TiO(2) layer modification on ITO/PEN substrates also played an important role in improving the transparency and the mechanical properties of the CE. The effect of the thickness of the TiO(2) layer for Pt coating on the performance of the CE was also investigated.

Electrodeposition of Platinum on Plastic Substrates as Counter Electrodes for Flexible Dye-Sensitized Solar Cells

Platinized electrodes were prepared by two-step constant current electrodeposition of Pt clusters on the Indium tin oxide-coated polyethylene naphthalate (ITO-PEN) substrates for use as counter electrodes in flexible dye-sensitized solar cells (DSSCs). The influence of the deposition conditions of two steps on the surface morphology of the deposited Pt was studied. Scanning electron microscopy and high-resolution transmission electron microscopy images showed the formation of well-separated and uniformly distributed Pt clusters on the substrates at optimum deposition conditions. The mean optical transmittance of the platinized electrodes was greater than 75% in the wavelength of 400–800 nm. The electrocatalytic activity for triiodide reduction was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical reduction was used as an effective post treatment method for further improving the performance of electrocatalytic activity and optical transmittance. X-ray photoelec...

Electrospun conductive polyaniline–polylactic acid composite nanofibers as counter electrodes for rigid and flexible dye-sensitized solar cells

Conductive polyaniline doped with 10-camphorsulfonic acid (PANI·CSA) blended with polylactic acid (PLA) composite films are directly deposited on rigid fluorine-doped tin oxide and flexible indium tin oxide-coated polyethylene naphthalate substrates by using a simple electrospinning method. The scanning electron microscope and atomic force microscope images show that the PANI·CSA–PLA film is assembled from about 200 nm-diameter nanofibers, with a generally uniform thickness of about 2 μm. The three-dimensional porous fibrous PANI·CSA–PLA films indicate good electrocatalytic performance for I3−/I− electrolyte, demonstrated by electrochemical impedance spectra and cyclic voltammetry measurements. The photoelectric conversion efficiency of the dye-sensitized solar cells (DSCs) firstly based on such rigid and flexible PANI·CSA–PLA counter electrodes achieves 5.3% and 3.1% under 1 sun illumination of 100 mW cm−2 (AM 1.5), respectively, which is close to that of sputtered Pt-based DSCs. In addition, the rigid PANI·CSA–PLA-based DSC demonstrates good stability. As the PANI·CSA–PLA counter electrodes can be obtained in a short time at room temperature, they are potentially applicable in large-area DSCs and suitable for flexible DSCs.

Enhanced Performance of Flexible Dye-Sensitized Solar Cells: Electrodeposition of Mg(OH)2 on a Nanocrystalline TiO2 Electrode

Nanocrystalline TiO2 photoanodes were prepared on a conductive indium–tin oxide coated polyethylene naphthalate (ITO-PEN) plastic substrate by the doctor-blade method to fabricate flexible dye-sensitized solar cells (DSCs). The surface of the photoanode was coated with Mg(OH)2 by electrodeposition and the deposition time was systematically varied (2, 4, 6, 8, and 10 min). Electrodeposited Mg(OH)2 was confirmed by IR and energy dispersive X-ray (EDX) analysis. The surface morphology was studied by scanning electron microscopy. The internal surface area of TiO2 was studied against the deposition time by taking into account the projected surface area of the photoelectrode and it shows that the internal surface area of the photoelectrode was reduced as the Mg(OH)2 deposition time increased. The performance of flexible DSCs on various deposition times of Mg(OH)2 was evaluated on the basis of their photocurrent density–voltage characteristics. Among the deposition times, 2 min showed the best performance in Voc...

Effect of Thin TiO2 Buffer Layer on the Performance of Plastic-based Dye-sensitized Solar Cells Using Indoline Dye

Photoelectric performance of plastic dye-sensitized solar cell (PDSC) using indoline dye D149 as an organic sensitizer was improved by introduction of a thin titania buffer layer on ITO-PEN (indium tin oxide coated polyethylenenaphthalate) film. With prominent increase in photocurrent density, open circuit voltage, and fill factor, the energy conversion efficiency of PDSC using D149 achieved 3.7%.

All-plastic dye-sensitized solar cell using a polysaccharide film containing excess redox electrolyte solution

All-plastic dye-sensitized solar cells (DSSCs) using TiO2 paste (SP-210), indium tin oxide-coated polyethylene naphthalate (PEN/ITO) film and a Pt-coated PEN/ITO film counter electrode, were fabricated with 1.0 wt% κ-carrageenan solid electrolyte containing the redox electrolytes (I-/I3-) solution. The cell performance of the all-plastic cell using 1.0 wt% κ-carrageenan solid electrolyte was investigated in comparison with liquid type one, showing that the values of Voc (open circuit voltage) and ff (fill factor) were the same, but Jsc (short circuit current) and η (conversion efficiency) were slightly larger for the liquid type electrolyte cell than the solid type one. A higher conversion efficiency was exhibited by UV-irradiation before heat treatment of the PEN/ITO/TiO2(SP-210) film than that after heat treatment. The effect of heat treatment conditions was investigated according to a modified hydrothermal treatment of the PEN/ITO/TiO2(SP-210) film, showing that the ff values become high (>0.7) by hydrothermal treatment. The electrochemical impedance spectroscopy (EIS) has shown the important comparison of each charge transport processes between the all-plastic and the conventional cells.