Zinc Oxide Dye-sensitized Solar Cell Research Articles

Fruit peels pigment extracts as a photosensitizer in ZnO-based Dye-Sensitized Solar Cells

Two of the most serious problems that we encounter today are the energy crisis and global warming. It has, therefore, become essential for a quest for clean and renewable energy sources, as the lasting solution for these problems. This paper presents the natural pigments from the facile extraction of fruit peels of Musa paradisiaca, Mangifera indica, Punica granatum, and Ananas comosus and their conversion efficiency in dye-sensitized solar cells (DSSCs). The zinc oxide (ZnO) photo-anode film was prepared and its properties were analyzed. Natural extracts were used as photosensitizers for constructing DSSCs. Characteristics of the natural Pigments were analyzed by various spectroscopy techniques. Solar to electrical energy efficiencies of natural dye-based on ZnO DSSCs were evaluated for Musa paradisiaca, Mangifera indica, Punica granatum, and Ananas comosus to be 0.009%, 0.024%, 0.010%, and 0.002%, respectively. The conversion of visible light into electricity resulting in improved photoelectric characteristics was achieved.

Enhanced photovoltaic performance and stability of dye-sensitized solar cells by utilizing manganese-doped ZnO photoanode with europium compact layer

Zinc oxide (ZnO)-nanoparticles based photoanodes are one of the most important photoanodes in dye-sensitized solar cells (DSSCs). However, ZnO-based photoanodes have disadvantages such as low photovoltaic performance and low stability compared to titanium dioxide (TiO2)-nanoparticles based photoanodes. In this current work, two different strategies have been simultaneously applied to eliminate these disadvantages of ZnO photoanodes and to prepare more efficient photoanode for DSSCs applications. In the first strategy, europium (Eu) compact layer has been deposited between fluorine-doped tin oxide (FTO) substrate and ZnO paste in order to increase the current density of DSSCs by benefiting down-conversion and photoluminescence properties of Eu. In the second strategy, manganese (Mn) ions have been doped into the ZnO structure at different ratios in order to enhance the electron transport mechanism of the ZnO photoanode and to increase the stability of the obtained DSSCs. As a result of these two strategies, the obtained DSSC performance with 1.0 mol% Mn doping and Eu compact layer showed a conversion efficiency of 4.20%, which is much higher than pure ZnO DSSC photoanode employing (1.45%). More importantly, the device showed considerable stability and repeatability under the constant light for 3000 s. Considering this improved performance and stability of DSSCs, this work may guide different lanthanide compact layers and different doping sources in order to further improve the performance and stability of DSSCs.

Performance of new single rhodanine indoline dyes in zinc oxide dye-sensitized solar cell

A new single rhodanine indoline dye GU112 having both cyanoacrylic and rhodanine acetic acid groups in an anchor moiety showed the best stability among GU110, GU111, and GU112 in zinc oxide dye-sensitized solar cell.

Etch-Resistant Zn1–xMgxO Alloys: An Alternative to ZnO for Carboxylic Acid Surface Modification

Zinc oxide (ZnO) is a high bandgap transparent metal oxide used extensively in organic electronic devices and dye-sensitized solar cells (DSSCs) as an electron accepting and transporting material. Carboxylic and other organic acid attachment schemes are often employed to sensitize or functionalize the surface of ZnO in these applications. Unfortunately, one weakness of ZnO is its high susceptibility to etching by even weak acids. This has a substantial negative impact on ZnO DSSCs which use carboxylic acid groups to attach dyes to ZnO and also influences attachment techniques for functionalizing ZnO in organic electronic devices. By substituting Mg for Zn atoms to form Zn1–xMgxO (ZnMgO) alloys, a material with similar electronic properties but higher etch resistance is achieved. Here, we show that the etch rate of Zn0.8Mg0.2O, when exposed to the prototypical modifier benzoic acid (BA), is an order of magnitude lower than that of ZnO. Infrared spectroscopic characterization of BA-modified ZnMgO indicates ...

Survey of co-adsorbent for DN350 in zinc oxide dye-sensitized solar cell

DN350 exhibited better performance than D149 in zinc oxide dye-sensitized solar cell in the presence of cholic acid (CA). The performance of DN350 was improved in the order of cholic acids: ursodeoxycholic acid (UDCA) > chenodeoxycholic acid (CDCA) > CA. This result could come from the bathochromic shift of the UV–vis absorption band of DN350 on zinc oxide to improve short-circuit photocurrent density.

Characterization of zinc oxide dye-sensitized solar cell incorporation with single-walled carbon nanotubes

Abstract

Morphological and electron transport studies in ZnO dye-sensitized solar cells incorporating multi- and single-walled carbon nanotubes

Dye-sensitized solar cells (DSSCs) incorporating zinc oxide (ZnO) nanostructures and carbon nanotubes (CNTs) were fabricated using a chemical bath deposition method. The nanoflake structures captured by a field-emission scanning electron microscopy analysis traced the appearance of multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) in the photoanode thin film. The photovoltaic performance of the photoanode was quantified by means of an electrochemical impedance spectroscopy (EIS) unit with GAMRY-Physical Electrochemistry. The ZnO–SWCNT-based DSSC exhibited good photovoltaic performance with power conversion efficiency (η), photocurrent density (Jsc), open-circuit voltage (Voc) and fill factor (FF) of 1.31%, 15.31 mA cm−2, 0.224 V and 0.36, respectively. The EIS unit was also employed to quantify the charge transport resistance (Rct), transport resistance (Rt) and effective electron lifetime (τeff) of the DSSC. The impedance analysis of the ZnO–SWCNT-based DSSC also determined greater highly efficient electron transport due to long effective electron diffusion length than the film thickness of the photoanode.

Optimization of dye adsorption time and film thickness for efficient ZnO dye-sensitized solar cells with high at-rest stability

Photoelectrodes for dye-sensitized solar cells were fabricated using commercially available zinc oxide (ZnO) nanoparticles and sensitized with the dye N719. This study systematically investigates the effects of two fabrication factors: the ZnO film thickness and the dye adsorption time. Results show that these two fabrication factors must be optimized simultaneously to obtain efficient ZnO/N719-based cells. Different film thicknesses require different dye adsorption times for optimal cell performance. This is because a prolonged dye adsorption time leads to a significant deterioration in cell performance. This is contrary to what is normally observed for titanium dioxide-based cells. The highest overall power conversion efficiency obtained in this study was 5.61%, which was achieved by 26-μm-thick photoelectrodes sensitized in a dye solution for 2 h. In addition, the best-performing cell demonstrated remarkable at-rest stability despite the use of a liquid electrolyte. Approximately 70% of the initial efficiency remained after more than 1 year of room-temperature storage in the dark. To better understand how dye adsorption time affects electron transport properties, this study also investigated cells based on 26-μm-thick films using electrochemical impedance spectroscopy (EIS). The EIS results show good agreement with the measured device performance parameters.

Application of novel N-(p-phenylene)-dicyanovinylidene double rhodanine indoline dye for zinc oxide dye-sensitized solar cell

Abstract A new indoline dye in which a double rhodanine acceptor is attached to the indoline moiety by a p-phenylene spacer on the indoline–nitrogen, has been examined for its performance as a sensitizer for zinc oxide dye-sensitized solar cells. In the presence of cholic acid, chenodeoxycholic acid, or lithocholic acid; the performance was greatest for lithocholic acid as this showed the greatest reduction in dye H-aggregate formation.

N-(2-Alkoxyphenyl)-substituted double rhodanine indoline dyes for zinc oxide dye-sensitized solar cell

The effect of N-(2-alkoxyphenyl) group in double rhodanine indoline dye on the performance of zinc oxide dye-sensitized solar cell was examined. Both Jsc and Voc were improved by introducing long alkoxy group due to prevention of H-aggregates formation and inhibition of electron recombination from zinc oxide surface to electrolyte.

Organic dyes containing fluorene-substituted indoline core for zinc oxide dye-sensitized solar cell

A novel idoline dye, having dimethylfluorene-substituted indoline donor and dicyanovinylidene-introduced rhodanine acceptor (DN350), gave much higher efficiency than D205 due to bathochromic absorption band and prevention of aggregates formation.

Effect of Nickel Oxide Thin Films on Photoconversion Efficiency in Zinc Oxide Dye-Sensitized Solar Cells

ZnO dye-sensitized solar cells (ZnO DSSCs) with different thickness of NiO thin films coated in photo-electrode and counter-electrode were investigated. NiO thin films were prepared by thermal evaporation of NiO onto FTO glass substrate. The films were characterized by FE-SEM. For the photo-electrode, NiO thin films were coated on ZnO with 0.2, 0.6, 1.1 and 2.2 mg to form a barrier layer. For the counter-electrode, NiO thin films were coated on FTO glass with 5.4, 10.8, 16.2 and 21.6 mg in order to increase a surface-to-volume ratio. The photoconversion efficiency of ZnO DSSCs was measured under illumination of stimulated sunlight obtained from solar simulator with the radiant power of 100 mW/cm2. It was found that ZnO DSSCs coated with 0.6 mg NiO in photo-electrode and 10.8 mg in counter-electrode exhibited the highest photoconversion efficiency of 1.00% and 0.92%, respectively. The enhancement of photoconversion efficiency with NiO coating maybe explained by decreasing of charge recombination in photo-electrode and increasing of active surface area in counter-electrode.

Highly efficient new indoline dye having strong electron-withdrawing group for zinc oxide dye-sensitized solar cell

New indoline dye (DN319) having strong electron-withdrawing dicyanovinylidene moiety and octyl group in the terminal rhodanine ring gave higher efficiency than D205, which was known as an excellent organic dye sensitizer. This result is attributed to the bathochromic shift in the UV–vis absorption band and positive shift in the E ox level of DN319.

Comparison of performance between benzoindoline and indoline dyes in zinc oxide dye-sensitized solar cell

The cell performance of novel benzoindoline dyes on zinc oxide prepared by template cathode electro-deposition method was compared with that of known indoline dyes. Among cyanoacrylic, single and double rhodanine acetic acid derivatives, the cyanoacrylic benzoindoline dye showed better performance than the indoline dye (D131) due to larger J sc value which comes from its positive E ox level and bathochromic UV–vis absorption band.

Highly efficient substituted triple rhodanine indoline dyes in zinc oxide dye-sensitized solar cell

Substituited triple rhodanine indoline dyes showed higher performance than known triple rhodanine derivative (D150). A few triple rhodanine indoline derivatives showed comparable conversion efficiency to D149.

Substituent effects in a double rhodanine indoline dye on performance of zinc oxide dye-sensitized solar cell

The solar-light-to-electricity conversion efficiency of substituted indoline dyes depended on short-circuit photocurrent density which is affected by maximum incident photon-to-current efficiency. The oxidation potential of the double rhodanine indoline dyes needed to be >∼0.2 V vs Fc/Fc + in acetonitrile to show high incident photon-to-current efficiency in a zinc oxide, dye-sensitized solar cell. To make a molecular design of highly efficient indoline dyes, the HOMO energy level should be more negative than ∼−4.9 eV by the DFT calculations.

The use of indoline dyes in a zinc oxide dye-sensitized solar cell

The effects of the position and the type of carboxyl anchor group in double rhodanine-type indoline dyes on the performance of a zinc oxide dye-sensitized solar cell were examined. The optimum position for the carboxymethyl group was on the inner rhodanine moiety; a carboxymethyl group gave optimum results among carboxymethyl, -ethyl, and -propyl derivatives.