scholarly journals Mesoporous TiO2 spheres as a photoanodic material in dye-sensitized solar cells

2018 ◽  
Vol 12 (4) ◽  
pp. 374-382 ◽  
Author(s):  
Nikola Tasic ◽  
Zorica Marinkovic-Stanojevic ◽  
Zorica Brankovic ◽  
Milan Zunic ◽  
Uros Lacnjevac ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solar Cells ◽  
Electrochemical Impedance ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Visible Region ◽  
Mesoporous Tio2 ◽  
Dye Sensitized ◽  
Bet Analysis ◽  
Sensitized Solar Cells

Mesoporous TiO2 films with spherical architectures and promising performance in dye-sensitized solar cells (DSSCs) were prepared. The morphology of the films was investigated by scanning electron microscopy. Transmission electron microscopy analysis of the spheres disclosed the elongated shape of sub-20 nm primary particles, while BET analysis revealed their high surface area of 135m2/g. Anatase presence was observed in the films based on X-ray diffractometry, selected-area electron diffraction analysis and Raman spectroscopy analyses. Increased light scattering of the spheres in visible region was observed by UV-VIS-NIR spectroscopy. Photovoltaic performance of the operating N719-sensitized cells was tested using electrochemical impedance spectroscopy and current density-voltage (J-V) curves under simulated AM1.5 spectrum. The 0.25 cm2 cells exhibited photo-to-electric power efficiency of 4.9%, which is among noteworthy values for DSSCs with similar photoanodic structures.

Analysis of Charge Transport and Recombination Studied by Electrochemical Impedance Spectroscopy for Dye-sensitized Solar Cells With Atomic Layer Deposited Metal Oxide Treatment on TiO2 Surface

2010 ◽  
Vol 1270 ◽  
Author(s):  
Braden Bills ◽  
Mariyappan Shanmugam ◽  
Mahdi Farrokh Baroughi ◽  
David Galipeau
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Atomic Layer ◽  
Back Reaction ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

AbstractThe performance of dye-sensitized solar cells (DSSCs) is limited by the back-reaction of photogenerated electrons from the porous titanium oxide (TiO2) nanoparticles back into the electrolyte solution, which occurs almost exclusively through the interface. This and the fact that DSSCs have a very large interfacial area makes their performance greatly dependant on the density and activity of TiO2 surface states. Thus, effectively engineering the TiO2/dye/electrolyte interface to reduce carrier losses is critically important for improving the photovoltaic performance of the solar cell. Atomic layer deposition (ALD), which uses high purity gas precursors that can rapidly diffuse through the porous network, was used to grow a conformal and controllable aluminum oxide (Al2O3) and hafnium oxide (HfO2) ultra thin layer on the TiO2 surface. The effects of this interfacial treatment on the DSSC performance was studied with dark and illuminated current-voltage and electrochemical impedance spectroscopy (EIS) measurements.

scholarly journals Photovoltaic Performance of Dye-Sensitized Solar Cells Containing ZnO Microrods

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1645 ◽  
Author(s):  
Seong Il Cho ◽  
Hye Kyeong Sung ◽  
Sang-Ju Lee ◽  
Wook Hyun Kim ◽  
Dae-Hwan Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Surface Area ◽  
Electrochemical Impedance ◽  
Collection Efficiency ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Charge Recombination ◽  
Growth Time ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

At an elevated temperature of 90 °C, a chemical bath deposition using an aqueous solution of Zn(NO3)2·6H2O and (CH2)6N4 resulted in the formation of both nanoflowers and microrods of ZnO on F-doped SnO2 glass with a seed layer. The nanoflowers and microrods were sensitized with dyes for application to the photoelectrodes of dye-sensitized solar cells (DSSCs). By extending the growth time of ZnO, the formation of nanoflowers was reduced and the formation of microrods favored. As the growth time was increased from 4 to 6 and then to 8 h, the open circuit voltage (Voc) values of the DSSCs were increased, whilst the short circuit current (Jsc) values varied only slightly. Changes in the dye-loading amount, dark current, and electrochemical impedance were monitored and they revealed that the increase in Voc was found to be due to a retardation of the charge recombination between photoinjected electrons and I3− ions and resulted from a reduction in the surface area of ZnO microrods. A reduced surface area decreased the dye contents adsorbed on the ZnO microrods, and thereby decreased the light harvesting efficiency (LHE). An increase in the electron collection efficiency attributed to the suppressed charge recombination counteracted the decreased LHE, resulting in comparable Jsc values regardless of the growth time.

scholarly journals Fabrication of TiO2/CdS heterostructure photoanodes and optimization of light scattering to improve the photovoltaic performance of dye sensitized solar cells (DSSCs)

2021 ◽  
Author(s):  
S. Revathi ◽  
A Pricilla Jeyakumari
Keyword(s):  
Solar Cells ◽  
Conversion Efficiency ◽  
Electrochemical Impedance ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Photocurrent Density ◽  
Cds Nanoparticles ◽  
Molar Ratios ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Abstract Currently, the TiO2/CdS photoanodes based dye sensitized solar cells (DSSCs) have shown extraordinary developments in the photo conversion efficiency. In this report, pristine TiO2, CdS and various molar ratios of TiO2/CdS photoanodes were prepared by one step microwave irradiation route and followed by doctor blade method. The sheet like morphology of the TiO2 and CdS nanoparticles were clearly evident from the SEM and TEM images. A significant reduction band gap with enhanced light absorption and rapid prevention of electron hole pair was explored by UV-DRS and PL studies. The photocurrent density-voltage (J-V) and electrochemical impedance (EIS) characteristics were analyzed for assembled solar cell. The photo-conversion efficiency of 12.8% was obtained with the configuration TiO2/CdS (200 mg) that represent a 2.5 fold increment compared to bare TiO2 (5.33%) as well as commercial Pt (6.11%). The experimental results are discussed.

scholarly journals Study on Carbon Nanocomposite Counterelectrode for Dye-Sensitized Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yiming Chen ◽  
Haiyan Zhang ◽  
Yuting Chen ◽  
Jiapeng Lin
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Composite Electrodes ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Carbon Nanocomposite ◽  
Nanocomposite Electrodes

Carbon nanocomposite electrodes were prepared by adding carbon nanotubes (CNTs) into carbon black as counterelectrodes of dye-sensitized solar cells(DSSCs). The morphology and structure of carbon nanocomposite electrodes were studied by scanning electron microscopy. The influence of CNTs on the electrochemical performance of carbon nanocomposite electrodes is investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Carbon nano composite electrodes with CNTs exhibit a highly interconnected network structure with high electrical conductivity and good catalytic activity. The influence of different CNTs content in carbon nanocomposite electrodes on the open-circuit voltage, short-circuit current, and filling factor of DSSCs is also investigated. DSSCs with 10% CNTs content exhibit the best photovoltaic performance in our experiments.

ZnO/TiO2 composite photoanodes for efficient dye-sensitized solar cells

2014 ◽  
Vol 07 (04) ◽  
pp. 1450039 ◽  
Author(s):  
Liqing Zhang ◽  
Shuai Zhou ◽  
Fengshi Cai ◽  
Zhihao Yuan
Keyword(s):  
Electron Microscopy ◽  
Solar Cells ◽  
Conversion Efficiency ◽  
Electrochemical Impedance ◽  
Hydrothermal Process ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Growth Time ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

ZnO / TiO 2 composite films composed of a ZnO nanoflowers overlayer and a ZnO / TiO 2 composite particulate underlayer were fabricated by a simple hydrothermal process. The as-prepared films were characterized by scanning electron microscopy, transmission electron microscopy (TEM) and diffused reflectance spectroscopy. The performance of dye-sensitized solar cells (DSCs) was investigated by photocurrent–voltage measurements, incident photon-to-current conversion efficiency (IPCE) and electrochemical impedance spectroscopy. It was found that the ZnO / TiO 2 composite film prepared with a 60 min growth time exhibited higher reflectivity than that of pure TiO 2 film due to the effective light-scattering of ZnO nanoflowers, resulting in increased J sc . In the meantime, the open-circuit potential of the device were enhanced from 698 to 826 mV due to the formation of an energy barrier by ZnO at TiO 2/electrolyte interface, resulting in a 52% improvement in the power conversion efficiency from 4.64 to 7.06%.

scholarly journals Effect of π-Conjugated Spacer in N-Alkylphenoxazine-Based Sensitizers Containing Double Anchors for Dye-Sensitized Solar Cells

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1304
Author(s):  
Yung-Sheng Yen ◽  
Velu Indumathi
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance ◽  
Power Conversion ◽  
Photovoltaic Performance ◽  
Co Adsorption ◽  
Dye Sensitized Solar Cells ◽  
Photovoltaic Properties ◽  
Dye Sensitized ◽  
The Impact ◽  
Sensitized Solar Cells

A series of novel double-anchoring dyes for phenoxazine-based organic dyes with two 2-cyanoacetic acid acceptors/anchors, and the inclusion of a 2-ethylhexyl chain at the nitrogen atom of the phenoxazine that is connected with furan, thiophene, and 3-hexylthiophene as a linker, are used as sensitizers for dye-sensitized solar cells. The double-anchoring dye exhibits strong electronic coupling with TiO2, provided that there is an efficient charge injection rate. The result showed that the power conversion efficiency of DP-2 with thiophene linker-based cell reached 3.80% higher than that of DP-1 with furan linker (η = 1.53%) under standard illumination. The photovoltaic properties are further tuned by co-adsorption strategy, which improved power conversion efficiencies slightly. Further molecular theoretical computation and electrochemical impedance spectroscopy analysis of the dyes provide further insight into the molecular geometry and the impact of the different π-conjugated spacers on the photophysical and photovoltaic performance.

scholarly journals Are Alkynyl Spacers in Ancillary Ligands in Heteroleptic Bis(diimine)copper(I) Dyes Beneficial for Dye Performance in Dye-Sensitized Solar Cells?

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1528 ◽  
Author(s):  
Guglielmo Risi ◽  
Mariia Becker ◽  
Catherine E. Housecroft ◽  
Edwin C. Constable
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Visible Region ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Ancillary Ligands ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

The syntheses of 4,4′-bis(4-dimethylaminophenyl)-6,6′-dimethyl-2,2′-bipyridine (1), 4,4′-bis(4-dimethylaminophenylethynyl)-6,6′-dimethyl-2,2′-bipyridine (2), 4,4′-bis(4-diphenylaminophenyl)-6,6′-dimethyl-2,2′-bipyridine (3), and 4,4′-bis(4-diphenylaminophenylethynyl)-6,6′-dimethyl-2,2′-bipyridine (4) are reported along with the preparations and characterisations of their homoleptic copper(I) complexes [CuL2][PF6] (L = 1–4). The solution absorption spectra of the complexes exhibit ligand-centred absorptions in addition to absorptions in the visible region assigned to a combination of intra-ligand and metal-to-ligand charge-transfer. Heteroleptic [Cu(5)(Lancillary)]+ dyes in which 5 is the anchoring ligand ((6,6′-dimethyl-[2,2′-bipyridine]-4,4′-diyl)bis(4,1-phenylene))bis(phosphonic acid) and Lancillary = 1–4 have been assembled on fluorine-doped tin oxide (FTO)-TiO2 electrodes in dye-sensitized solar cells (DSCs). Performance parameters and external quantum efficiency (EQE) spectra of the DSCs (four fully-masked cells for each dye) reveal that the best performing dyes are [Cu(5)(1)]+ and [Cu(5)(3)]+. The alkynyl spacers are not beneficial, leading to a decrease in the short-circuit current density (JSC), confirmed by lower values of EQEmax. Addition of a co-absorbent (n-decylphosphonic acid) to [Cu(5)(1)]+ lead to no significant enhancement of performance for DSCs sensitized with [Cu(5)(1)]+. Electrochemical impedance spectroscopy (EIS) has been used to investigate the interfaces in DSCs; the analysis shows that more favourable electron injection into TiO2 is observed for sensitizers without the alkynyl spacer and confirms higher JSC values for [Cu(5)(1)]+.

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