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1.
AbstractA ZnO modified TiO2 (ZnO/TiO2) film was prepared by immersing TiO2 electrodes in Zn(Ac)2 aqueous solution. The open circuit voltage of a dye sensitised solar cell (DSSC) with the ZnO/TiO2 film electrode has a dramatic enhancement, compared to the DSSC with the TiO2 film electrode. However, the short circuit current density of the DSSC with the ZnO/TiO2 film electrode is lower than that with TiO2 electrode. The film electrodes were characterised by SEM, EDX and UV-vis, and the photoelectric performance of DSSCs were measured. The photovoltage enhancement is attributed to the formation of a flat-band potential energy barrier by ZnO at TiO2/electrolyte interface. The decline of the photocurrent with ZnO/TiO2 film electrode is due to poor dye absorption on larger particles of ZnO. 相似文献
2.
This study investigates the effect of a ZnO-coated TiO2 working electrode on the power conversion efficiency of a dye-sensitized solar cell (DSSC). This electrode was designed and fabricated by dipping the TiO2 electrode with the TiCl4 treatment in a solution of zinc acetate dehydrate [Zn(CH3COO)2·2H2O] and ethanol. The effects of the concentration of Zn(CH3COO)2·2H2O and the duration of dipping on the band gap of a working electrode and the power conversion efficiency of a DSSC were also examined. The band gap of the working electrode increases to 3.75 eV [TiO2 electrode dipped in 0.05 M Zn(CH3COO)2·2H2O) for 3 min] from 3.22 eV (TiO2 electrode). Interestingly, the power conversion efficiency of the DSSC with a Zn-coated TiO2 electrode (6.7%) substantially exceeds that of the conventional DSSC with a TiO2 electrode (5.9%), and it may be originated from an increased energy barrier between ZnO and TiO2 that reduces the electron recombination rate. 相似文献
3.
A quasi solid-state dye-sensitized solar cell (DSSC) is fabricated using 1-propyl-3-methylimidazolium iodide (PMII) and polyaniline-loaded carbon black (PACB) as the composite electrolyte. The electrolyte without added iodine is sandwiched between TiO2 working electrode and platinum counter electrode (CE). A power conversion efficiency (η) of 5.81% is achieved with this type of cell. With the addition of 1-ethyl-3-methylimidazolium thiocyanate (EMISCN), a low-viscosity ionic liquid (IL), the cell with the binary ionic liquid (bi-IL) renders an efficiency of 6.15%, the best for any quasi solid-state DSSC without the addition of iodine. To fabricate a low cost DSSC using the bi-IL, the platinum layer of the counter electrode is replaced with a polymer layer, 3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4] dioxepine (PProdot-Et2) through electrodeposition, and the corresponding DSSC shows an efficiency of 5.27%. At-rest stability of the quasi solid-state DSSC with bi-IL is compared with that of a liquid electrolyte DSSC at room temperature; the power conversion efficiency of the former shows a decrease of hardly 3% after 1000 h, while that of the latter shows a decrease of about 30%. The quasi solid-state cell shows unfailing durability at 70 °C. 相似文献
4.
An unusual double-layered TiO2 (bottom layer)/Bx–TiO2 (top layer) combined electrode array was investigated to improve the photocurrent in dye-sensitized solar cells (DSSCs). A positive semiconductor, Bx–TiO2, with nanometer-sized B (1.0, 5.0, and 10.0 mol%)-incorporated TiO2 prepared using a solvothermal method, was utilized as the working electrode material by coating onto the second level above the TiO2 electrode. The photocurrent and photovoltaic efficiency of the TiO2 (bottom)/Bx–TiO2 (top)-DSSC were 20.5% and 17.3% greater, respectively, than that of the double-layers of anatase TiO2–DSSC in the photocurrent–voltage (I–V) curve of the optimal electrode. This result was attributed to their energy levels of reduction (LUMO)/oxidation (HOMO) as determined by cyclic voltammetry (CV). As the LUMO level of Bx–TiO2 was located at a slightly higher level than that of pure anatase TiO2, the electrons donated from the dye were easily transferred to the surface of the TiO2 electrode without electron loss. Moreover, the recombination was also much slower in the TiO2 (bottom)/Bx–TiO2 (top)-based DSSCs than in the double-layered pure TiO2 DSSC. 相似文献
5.
Song-Rim Jang Min-Jung Choi R. Vittal Kang-Jin Kim 《Solar Energy Materials & Solar Cells》2007,91(13):1209-1214
A synthetic route was developed to link N3 dye to polyacrylic acid (PAA) using ethylenediamine (en) as the linker. The resulting complex, PAA–en–N3, was then coated onto a TiO2 film. The modified TiO2 film electrode (hereafter PAA–en–N3/TiO2), when used as the photoanode in a dye-sensitized solar cell (DSSC), exhibited enhanced solar energy conversion efficiency compared with that of the usual DSSC with the N3/TiO2 film electrode. The increase in efficiency was attributed to the increased open-circuit voltage (Voc) and short-circuit photocurrent (Jsc). The increase in Voc was attributed to the formation of a hydrophobic PAA–en–N3 layer on the TiO2/electrolyte interface, while the increase in Jsc was attributed to the additional dye acquired by the TiO2 film from the PAA–en–N3 complex. 相似文献
6.
The effects of TiO2 photoelectrode's surface morphology and different solvents on the photovoltaic performance of dye-sensitized solar cells (DSSCs) were studied. By successive coating of TiO2 suspension, composed of low and high molecular weight poly(ethylene)glycol (PEG) as a binder, double layered TiO2 photoelectrodes with four different structures were obtained. Among the DSSCs with different TiO2 electrodes, DSSC with P2P1 electrode (P2 and P1 correspond to PEG molecular weights of 20,000 and 200,000, respectively) showed higher performance under identical film thickness at a constant irradiation of 100 mW cm−2, which may be correlated with large pore size and high surface area of the corresponding TiO2 electrode. This was confirmed by electrochemical impedance spectroscopy (EIS) analysis of the DSSC and the transient photovoltage measurement of electrons in the TiO2 electrode. Among the different solvents investigated here, the DSSC containing acetonitrile showed high conversion efficiency and the order of performance of the DSSCs with different solvents were AN > MPN > PC > GBL > DMA > DMF > DMSO. Better correlation was observed between the donor number of solvents and photoelectrochemical parameters of the DSSCs containing different solvents rather than the measured viscosity and dielectric constant of solvents. The reasons for the low performance of the DSSCs containing DMA, DMSO and DMF, respectively, were due to the negative shift of TiO2 conduction band and the desorption of dye molecules from the TiO2 photoelectrode by those solvents. 相似文献
7.
Jin-A JeongHan-Ki Kim 《Solar Energy Materials & Solar Cells》2011,95(1):344-348
We report on the characteristics of a TiO2 passivating layer grown by radio frequency (RF) magnetron sputtering on F-doped SnO2 (FTO) electrodes as a function of its thickness. The optical transparency, surface roughness and passivation properties of the TiO2 layer passivating the FTO electrode depend on the thickness of the TiO2 passivating layer. In addition, it was found that the power conversion efficiency of the dye-sensitized solar cells (DSSCs) is critically dependent on the thickness of RF sputtered TiO2 layer inserted between FTO electrode and nanoporous TiO2 layer. The DSSC fabricated on 50 nm thick TiO2 passivating FTO electrode showed the maximum power conversion efficiency of 4.42% due to effective prevention of the electron transfer to electrolyte. This indicates that the thickness optimization of the TiO2 passivating layer is one of the important parameter to obtain high performance DSSCs. 相似文献
8.
Plastic dye-sensitized photo-supercapacitor using electrophoretic deposition and compression methods
Hsin-Wei Chen Jian-Ging Chen Chun-Chieh Wang Kuo-Chuan Ho 《Journal of power sources》2010,195(18):6225-17518
A plastic photo-rechargeable capacitor is studied using a three-electrode configuration, separating a flexible dye-sensitized solar cell (DSSC) and a supercapacitor by sharing a common Pt electrode. The thick and uniform TiO2 film is formed by using commercially available TiO2 nanocrystals, which are treated in an isopropyl alcohol without surfactant by the electrophoretic deposition (EPD) to deposit the mesoporous TiO2 photoanode film with good adherence onto the plastic substrate. Afterward, a static mechanical compression technique as the post-treatment is employed to the electrophoretic deposited film in order to enhance the particles connection. In addition, a supercapacitor using PEDOT (poly(3,4-ethylenedioxythiophene)), which is potentiostatically electropolymerized to form a thick film, is fabricated to store the energy. The flexible DSSC part is fabricated with a TiO2 film of 10.9 μm thickness and it can provide photoelectric conversion efficiency up to 4.37% under 1 sun illumination. The photocapacitor is made with such a flexible DSSC and a supercapacitor with ca. 0.5 mm thick PEDOT film, which provides a specific capacitance of 0.52 F cm−2. 相似文献
9.
TiO2/ZnO/Eosin Y structure films were prepared by a one-step cathodic electrodeposition method and used as a photoanode in a dye-sensitized solar cell (DSSC). Using this TiO2/ZnO/Eosin Y electrode in DSSC, the degradation of the cell with time was reduced and ISC, VOC and fill factor values were increased. The use of a thin ZnO layer, permitted the formation of an energy barrier at the electrode/electrolyte interface, thus reducing recombination rate and improving cell performance. In addition, the adsorbed dye molecules prepared by one-step cathodic electrodeposition with ZnO were very stable compared with that prepared by conventional immersing method, as evidenced by UV/vis absorption spectroscopy measurements. 相似文献
10.
Aazam Nasirian Valliolah Mirkhani Majid Moghadam Shahram Tangestaninejad Iraj Mohammadpoor-Baltork Reza Keshavarzi 《Applied Solar Energy》2016,52(1):32-39
In this work, nanocrystalline P25 TiO2 films with different thicknesses were deposited on FTO coated glass substrates by an electrophoretic deposition technique (EPD) and applied as the work electrode for dye-sensitized solar cells (DSSC) using cis-bis(isothiocyanato)(2,2'-bipyridyl-4,4'-dicarboxylato)(4,4'di-nonyl-2'-bipyridyl) ruthenium(II) (Z907, Dyesol) as sensitizing dye.The results showed that the increasing the thickness of TiO2 films lead to increase the adsorption of the dye on the TiO2 layers which in turns improved the short-circuit photocurrent (Jsc) and open-circuit voltage (Voc), respectively. Furthermore, it was found that the effects of the surface states on the recombination of the photo-injected electrons (electron–hole pairs) in the TiO2 films strongly depend on theTiO2 electrode annealing temperature. Finally, a DSSC with a 32.82 μm thickness for TiO2 film annealed at 600°C produced the highest conversion efficiency with an incident solar energy of 100 mW/cm2 (η = 8.23%, Jsc = 15.98, Voc = 0.73, FF = 0.7). 相似文献
11.
Sarmimala Hore Carmen Vetter Rainer Kern Herman Smit Andreas Hinsch 《Solar Energy Materials & Solar Cells》2006,90(9):1176-1188
Thin titaniumdioxide (TiO2) semiconductor layer with different scattering layers was investigated in dye-sensitized solar cells (DSSC). Since the cost of the photoactive dye in the DSSC is relatively high, it is reasonable to assume that the price of the dye could be one of the decisive factors in determining the price of the DSSC modules. Use of a thin layer of nanocrystalline TiO2 would imply reduction in the amount of dye coverage, however, lower amount of dye in the thin films would imply fewer electron generation upon illumination. Thus, it becomes necessary to include a light scattering layer such that the lower photon conversion due to thin layer could be compensated. In the present study up to 80% increase in current density was observed due to inclusion of scattering layers. Reflectance and transmittance measurements were employed in order to study the optical properties of these scattering layers. The scattering layers, which are considered here, are TiO2-Rutile, zirconiumdioxide (ZrO2), and layers consisting of these two in various proportions. With a 4 μm thin titanium dioxide semiconductor layer as photo electrode and an additional light scattering layer (consisting of TiO2-Rutile and ZrO2 in a ratio of 1:3), efficiencies of 6.8% were achieved. 相似文献
12.
Reduced graphene oxide–titania nanocomposite‐modified photoanode for efficient dye‐sensitized solar cells
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We report the successful application of reduced graphene oxide–titania (rGO–TiO2) nanocomposite as an efficient photoanode for dye‐sensitized solar cell (DSSC). The DSSC assembled with the rGO–TiO2‐modified photoanode demonstrated an enhanced solar to electrical energy conversion efficiency of 4.74% compared with the photoanode of DSSC composed with unmodified TiO2 (2.19%) under full sunlight illumination (100 mW/cm2, AM 1.5G) as a result of the better charge collection efficiency of rGO, which reduced the back electron transfer process. Influence of the rGO content on the overall efficiency was also investigated, and the optimal rGO content for TiO2 was 0.5 mg. Further, the modification of rGO–TiO2 on the compact layer TiO2 surface led to an increase in efficiency to 5.83%. The superior charge collection and enhanced solar energy conversion efficiency of the rGO–TiO2 nanocomposite makes it to be used as a promising alternative to conventional photoanode‐based DSSCs. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
13.
Dye sensitized solar cell (DSSC) can be an economically viable and technically simpler alternate to the silicon based solar cells. Films of nanocrystalline titanium dioxide (TiO2) are considered as the most suitable photoelectrode for DSSC. For this study, TiO2 powder of anatase phase, synthesized in acidic environment was used. The average diameter of the nanoparticles was ~20 nm and BET surface area was 64.68 m2/g. Different TiO2 pastes were prepared by varying the proportion of TiO2 powder, α-terpineol, and ethyl cellulose (EC) in their composition. The TiO2 paste was cast on fluorine doped tin oxide (FTO) coated glass surface using doctor blade to prepare photoelectrode of TiO2 film. Composition of the paste ingredients was optimized by comparing the conversion efficiencies of the DSSCs fabricated with the photoelectrode of thickness ~18 μm. The outcome of this study can be crucial for the preparation of reliable TiO2 paste in a simple way for its application in DSSC. 相似文献
14.
In this paper, novel TiO2 submicro-rings were synthesized via potentiostatic anodization of titanium powder coated on transparent conducting oxide glass. The TiO2 submicro-rings film was characterized by SEM, XPS and 3D optical profiling. Accordingly, a possible growth mechanism of submicro-rings was discussed. The TiO2 submicro-rings based dye-sensitized solar cell (DSSC) with the film thickness of ca. 3.1 μm was assembled and a conversion efficiency of 1.36% was achieved under AM 1.5 illumination. The photoelectron transport properties of TiO2 submicro-rings based DSSC were also discussed according to the electron impedance spectroscopy. 相似文献
15.
A solid-state dye-sensitized solar cells (DSSC) comprising of p-type NiO thin layer on TiO2 was fabricated in which the dye is adsorbed on the p-type oxide and the thin NiO layer acts as a hole collector as well as a barrier for charge recombination. DSSC with NiO-coated TiO2 electrodes with Ru-dye delivers Isc=0.15 mA and Voc=480 mV. It was shown that the p-type oxide materials could be successfully used to construct DSSC and the plausible charge transfer mechanism is discussed. 相似文献
16.
N. Ghraïri 《国际可持续能源杂志》2016,35(5):469-477
Titanium dioxide- (TiO2) based photo-electrode for dye-sensitised solar cells (DSSCs) use is fabricated with the electro-phoretic deposition (EPD) technique on indium-tin-oxide (ITO). TiO2 films were synthesised at different EPD biases ranging from 70 to 110 V. We correlate the morphological and optical properties of formed films to the electrical characteristics of fabricated DSSCs. In addition, by neglecting the tunnelling and the tunnelling-assisted thermo-ionic currents with respect to the pure thermo-ionic current at the ITO/TiO2 interface, we evaluate the high potential barrier, e?B. Investigation of the electrical properties of the formed DSSCs shows a best result when the TiO2 film is elaborated at 100 V. Furthermore, by taking into account the high band energy of 0.6 eV at an aluminium-based counter electrode/electrolyte interface, we deduce that aluminium reduces drastically the short-circuit current of the DSSC. 相似文献
17.
Jian-Ging Chen Shi-Jhang Wu Chun-Guey Wu Kuo-Chuan Ho 《Solar Energy Materials & Solar Cells》2008,92(12):1723-1727
In this study, the photoelectrochemical characteristics of a ruthenium photosensitizer with an alkyl bithiophene group, designated as CYC-B1, are studied. The effect of mesoporous TiO2 film thickness on the photovoltaic performance of CYC-B1 and N3 dye-sensitized solar cells was investigated. The performance of the dye-sensitized nanocrystalline TiO2 solar cells (DSSC) fabricated using CYC-B1 dye-anchored TiO2 photoelectrode showed a convincing enhancement in cell efficiency when the TiO2 film thickness was increased from 3 μm (eff.=5.41%) to 6 μm (eff.=7.19%). The efficiency of the CYC-B1-sensitized DSSC was maximum at 6 μm of the TiO2 film thickness, reached its limiting value and remained constant up to 53 μm, although a similar trend was also observed for N3 dye-sensitized DSSC, however, the maximum efficiency achieved was only at 27 μm thickness (eff.=6.75%). As expected, the photocurrent density generated in the DSSC modified by CYC-B1 dye is larger than that from N3 dye. The effect of guanidinium thiocyanate (GuSCN) (additive) addition to the electrolyte on the photovoltaic performance of DSSCs based on CYC-B1 was also investigated. Furthermore, the electrochemical impedance spectroscopy (EIS) technique and photo-transient laser method have been employed to analyze the charge transfer resistances (Rct) and the lifetime of the injected electrons on the TiO2 containing different thicknesses. 相似文献
18.
Youngsoo Kim Beom Jin Yoo R. Vittal Yeonhee Lee Nam-Gyu Park Kang-Jin Kim 《Journal of power sources》2008
The effects of low-temperature O2 plasma treatment of a TiO2 film are studied with the objective of improving the performance of dye-sensitized solar cells (DSSCs). X-ray photoelectron spectra (XPS) reveal that the ratio of titanium dioxide to titanium sub-oxides is increased in the O2 plasma-treated TiO2 film, compared with that of the untreated TiO2 film. This increase suggests that the oxygen vacancies in the film are effectively reduced. The near-edge X-ray absorption fine structure (NEXAFS) spectra results agree with the XPS result. It is proposed that there is a correlation between the shifts of the peaks in the NEXAFS spectra and the adsorption of N719 dye on the TiO2 particles. A DSSC having an O2 plasma-treated, 4 μm thick TiO2 film electrode renders a short-circuit photocurrent of 7.59 mA cm−2, compared with 6.53 mA cm−2 for a reference cell with an untreated TiO2 electrode of the same thickness. As a result of these changes, the solar-to-electricity conversion efficiency of the O2 plasma-treated cell is found to be 4.0% as compared with 3.5% for the untreated cell. This improvement in the performance is rationalized on the basis of increased N719 dye adsorption on to the TiO2, due to the reduction in the number of oxygen vacancies caused by the oxygen plasma treatment. 相似文献
19.
Surface tailoring and functionalization of an annealed TiO2 compact layer by H2SO4 acid was performed to improve the dye-sensitized solar cell (DSSC) performance. Compared to untreated counterpart, the acid-treated compact layer possesses a rougher surface and more hydroxyl groups, which result in increased surface area and enhanced adherence of the compact layer with the mesoporous TiO2 film by Ti–O–Ti bonds formed by a followed heating process. Impedance measurement was further used to investigate the enhancement mechanism, indicating the acid post treatment of the TiO2 compact layer reduces the ohmic bulk resistivity while effectively suppressing charge recombination at FTO/electrolyte interface. In DSSCs with untreated TiO2 compact layer, a significantly increased series resistivity is very likely to be the rate determining factor to limit the charge separation process. Thus, an optimal post acid treatment could reduce the resistivity for high charge transport, resulting in larger short-circuit current for further improvement of power conversion efficiency from 6.60% in DSSC with untreated compact layer to 7.21% in DSSC with acid-treated compact layer. This work also provides fundamental insight of the compact layer for DSSC performance improvement. 相似文献
20.
Nofrijon Sofyan Aga Ridhova Akhmad H. Yuwono Arief Udhiarto Jeffrey W. Fergus 《国际能源研究杂志》2019,43(11):5959-5968
Efficiency of a dye‐sensitized solar cell (DSSC) device depends on its semiconductor layer and the sensitizing dye to absorb the light. This work seeks to obtain the best solvent for the natural dye extraction from Melastoma malabathricum L. seeds. The extracted dye is used as sensitizer on TiO2 nanoparticles produced via hydrothermal but optimized at relatively low temperature. Infrared characterization of the extracted dyes showed differences in functional groups using different solvents, whereas ultraviolet visible examination of the dyes showed differences in intensity along the spectrum ranges of 600 to 400 nm with maximum absorption around 550 to 500 nm. Thermal analysis revealed that the natural dye should be stable around room temperature. Analysis on the synthesized TiO2 nanoparticles showed that the average crystallite size reported in the previous work is consistent with crystallite sizes observed in the transmission electron microscope images. Photoactivity examination showed that the DSSC sensitized using natural dye extracted with ethanol containing 20% distilled water on TiO2 synthesized at 150°C has an efficiency of 5.7%, whereas the one on commercial TiO2 P25 Degussa has an efficiency of 3.0%. The DSSC device sensitized using commercial dye on TiO2 synthesized at 150°C has an efficiency of 4.4%, whereas the one on TiO2 P25 Degussa has an efficiency of 4.0%. This result is promising for further development of the DSSC device using TiO2 nanoparticles synthesized at low hydrothermal temperature and sensitized with the natural dye. 相似文献