Improved Photovoltaic Properties Of Dye-Sensitized Solar Cells Using Laser Patterned F-Doped SnO2 Thin Films (original) (raw)
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We report the fabrication and testing of dye sensitized solar cells (DSSC) based on tin oxide (SnO 2) particles of average size ~20 nm. Fluorine-doped tin oxide (FTO) conducting glass substrates were treated with TiO x or TiCl 4 precursor solutions to create a blocking layer before tape casting the SnO 2 mesoporous anode. In addition, SnO 2 photoelectrodes were treated with the same precursor solutions to deposit a TiO 2 passivating layer covering the SnO 2 particles. We found that the modification enhances the short circuit current, open-circuit voltage and fill factor, leading to nearly 2-fold increase in power conversion efficiency, from 1.48% without any treatment, to 2.85% achieved with TiCl 4 treatment. The superior photovoltaic performance of the DSSCs assembled with modified photoanode is attributed to enhanced electron lifetime and suppression of electron recombination to the electrolyte, as confirmed by electrochemical impedance spectroscopy (EIS) carried out under dark condition. These results indicate that modification of the FTO and SnO 2 anode by titania can play a major role in maximizing the photo conversion efficiency.
Ceramics International, 2012
F-doped SnO 2 (FTO) glass substrate was successfully fabricated via spray-pyrolysis deposition for use as a transparent conducting substrate in dye-sensitized solar cells (DSSCs). To investigate the performance dependence of DSSCs on the sheet resistance of the FTO films, three types of FTO films with sheet resistance values of 2 V/&, 4 V/&, and 10 V/& were fabricated. Commercial FTO films having a sheet resistance of 15 V/ & were prepared for comparison. The structural, electrical, and optical properties of FTO films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), the four-point probe method, and UV-vis spectrometry. The photocurrent-voltage data show that DSSCs fabricated with a sheet resistance of 2 V/& exhibit the best photoconversion effciency ($5.5%) among the four samples. The performance improvement of DSSCs is due to improved short-circuit current density ($13.7 mA/cm 2
CHIMIA International Journal for Chemistry, 2013
This paper describes the synthesis and characterization of core-shell structures, based on SnO2 and TiO2, for use in dye-sensitized solar cells (DSC). Atomic layer deposition is employed to control and vary the thickness of the TiO2 shell. Increasing the TiO2 shell thickness to 2 nm improved the device performance of liquid electrolyte-based DSC from 0.7% to 3.5%. The increase in efficiency originates from a higher open-circuit potential and a higher short-circuit current, as well as from an improvement in the electron lifetime. SnO2-TiO2 core-shell DSC devices retain their photovoltage in darkness for longer than 500 seconds, demonstrating that the electrons are contained in the core material. Finally core-shell structures were used for solid-state DSC applications using the hole transporting material 2,2',7,7',-tetrakis(N, N-di-p-methoxyphenyl-amine)-9,9',-spirofluorene. Similar improvements in device performance were obtained for solid-state DSC devices.
Surface properties of SnO2 nanowires for enhanced performance with dye-sensitized solar cells
2009
Our recent studies showed that nanowire based DSSCs exhibited over 250 mV higher open circuit potentials (V OC) compared to those using nanoparticles. In this study, the electron transport and surface properties of nanowires and nanoparticles are investigated to understand the reasons for the observed higher photovoltages with NW based solar cells. It was seen that, in addition to slow recombination kinetics, the lower work function of SnO 2 nanowires compared to the nanoparticle counterparts also significantly contributes to the high V OC observed for the nanowire based DSSCs.
Influences of textures in fluorine-doped tin oxide on characteristics of dye-sensitized solar cells
Organic Electronics, 2011
We investigated the influences of textures in the transparent conductor fluorine-doped tin oxides (FTO) on characteristics and performances of dye-sensitized solar cells (DSSCs). FTO conductors having varied textures were characterized for their physical, electrical and optical properties and were subjected to device studies to establish the correlation between FTO textures and DSSC characteristics/performances. The results suggest that the highly textured and high-haze FTO can effectively scatter a portion of the incident light into larger angles in the device, enhancing the propagation length and trapping of the incident light within the device and contributing to significant enhancement of absorption (and thus short-circuit current, quantum efficiency, and power conversion efficiency) in the device configuration. As a result, the conversion efficiency of the DSSC was enhanced from 8.18% to 10.1%, an improvement by 24%, with using the highly textured, large-roughness and high-haze FTO as the transparent conductor.
Tin oxide as a photoanode for dye-sensitised solar cells: Current progress and future challenges
Tin oxide (SnO2) is a candidate for applications requiring high electrical conductivity and optical transparency, such as a photoanode in dye-sensitised solar cells (DSSCs), due to its higher electron mobility and wider optical transparency than many other metal oxide semiconductors (MOS), such as TiO2 and ZnO. However, DSSCs employing SnO2 show significantly lower photoconversion efficiency, compared to that achieved by popular choices, such as TiO2, due to its intrinsic limitations such as lower conduction band energy and isoelectric point. A survey of literature shows a revived interest in SnO2- based DSSCs, for example, strategies to (i) increase the dye uptake, (ii) increase its Fermi energy level, and (iii) reduce the recombination, such as by increasing surface roughness and novel morphologies towards (i), and doping of transition metals for (ii) and (iii). In response to these improvements, SnO2-based DSSCs showed similar open circuit voltage and superior short circuit current to that achieved by TiO2. We have undertaken a critical review on the progress made in overcoming the limitations and capitalising the advantages of SnO2 to fabricate more efficient DSSCs.We identify that more investment is required to reduce the recombination in SnO2 for it to emerge as an efficiency record holder in DSSCs
Influence of TiO2 Film Thickness on the Electrochemical Behaviour of Dye-Sensitized Solar Cells
International Journal of Electrochemical Science
A commercial TiO 2 powder was deposited on F-doped SnO 2 (FTO) glass substrates by a spray coating technique with different thicknesses (6, 10 and 14 µm) to be used as photo-anode in dye-sensitized solar cells (DSSCs). N3 dye was adsorbed on each TiO 2 film for 16 h. The resulting electrodes were used to form dye-sensitized solar cells in combination with conventional electrolyte and counterelectrode. The cells were investigated by I-V characteristics and electrochemical impedance spectra. The cell formed with a TiO 2 film of 10 µm thickness reached the best performance. This thickness resulted as the best compromise in terms of absorption of incident light on the N3 dye, reduction of the recombination processes and suitable series and charge transfer resistance
Journal of Solid State Electrochemistry, 2016
Current collector is an important part of nanostructured dye-sensitized solar cells (DSSCs), which reduces ohmic loss. In the present work, Ni current collector was electrochemically deposited on fluorine-doped tin oxide (FTO) for use as current collector of DSSC. The adhesion of Ni to FTO was improved by post-annealing in ambient atmosphere. A new method was proposed to prevent Ni coating from oxidation during annealing. According to this method, a carbon over-layer was applied on Ni coating, which protected Ni from oxidation. Visual inspection and X-ray diffraction (XRD) results showed the effectiveness of this method in protection of Ni coating from oxidation. Furthermore, the effect of current collector on photovoltaic performance of DSSCs was investigated using current density-voltage curve measurement and electrochemical impedance spectroscopy methods. It was observed that post-annealing in ambient atmosphere, under protection of carbon over-layer, improves both the adhesion of Ni current collector to FTO and the photovoltaic performance of DSSC. However, Ni oxidation during post-annealing of Ni current collector, without carbon over-layer, significantly decreased the photovoltaic parameters of DSSC. The above observations were explained by considering the series resistance of DSSC.
Fabrication of nanocomposited Sn-doped ZnO/TiO₂ based dye-sensitized solar cells / Saurdi Ishak
2018
Dye-sensitized solar cells (DSSCs) that belong to the third generation of solar cells are attractive due to cheap and ease of solar cell fabrication. Therefore, much research has been conducted to create an efficient solar cell. The following research illustrates for the first time development of aligned ZnO nanorod on Sn-doped ZnO films by using sonicated sol-gel immersion methods for dye-sensitized solar cells and the fabricated DSSCs show the improvement of photovoltaic properties and than from a novel photoanode of nano-composited aligned ZnO nanorod/TiO2:Nb a significant improvement on photovoltaic properties was obtained. The Sn-doped ZnO films were used as a seed layer for nanorod growth, where the Sn-doped ZnO films at 2 at.% shows the best of electrical and optical properties. As a result, the aligned ZnO nanorod with relatively high aspect ratio was grown on ITO-coated glass at 2 at.% Sn-doped ZnO films using sonicated sol-gel immersion methods. The resulting of ZnO nanoro...