Photoelectrodes In Dye-sensitized Solar Cells Research Articles

Development of Ultra-Thin TiO2 Coated WO3 Inverse Opal Photoelectrode for Dye-Sensitized Solar Cells

In this study, we prepare pure WO3 inverse opal(IO) film with a thickness of approximately 3 μm by electrodeposition, and an ultra-thin TiO2 layer having a thickness of 2 nm is deposited on WO3 IO film by atomic layer deposition. Both sets of photoelectrochemical properties are evaluated after developing dye-sensitized solar cells(DSSCs). In addition, morphological, crystalline and optical properties of the developed films are evaluated through field-emission scanning electron microscopy(FE-SEM), High-resolution transmission electron microscopy(HR-TEM), X-ray diffraction(XRD) and UV/ visible/infrared spectrophotometry. In particular, pure WO3 IO based DSSCs show low VOC, JSC and fill factor of 0.25 V, 0.89 mA/cm2 and 18.9 %, achieving an efficiency of 0.04 %, whereas the TiO2/WO3 IO based DSSCs exhibit VOC, JSC and fill factor of 0.57 V, 1.18 mA/cm2 and 50.1 %, revealing an overall conversion efficiency of 0.34 %, probably attributable to the high dye adsorption and suppressed charge recombination reaction.

Effects of TiO2 Coating on WO3 Inverse Opal Photoelectrode for Dye-sensitized Solar Cells

This study is based on Research and Education (R&E) project in science high school. In this study, we compared the photoelectrochemical properties of pure WO3 and TiO2 coated WO3 inverse opal film after the development of dye-sensitized solar cells (DSSCs). That is, above the SnO2 inverse opal (IO), thin WO3 film was prepared by the facile electrodeposition, subsequently forming the TiO2 layer by dipping in the 0.05 M or 0.005 M TiCl4 solution. Their morphological, crystalline, optical and photoelectrochemical properties of the developed films and composed DSSCs were evaluated exploring the field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectrophotometer and solar simulator. In particular, the fill factor of pure WO3 coated SnO2 IO, 0.005 M TiCl4 treated WO3/SnO2 IO and 0.05 M TiCl4 treated WO3/SnO2 IO existed in the similar value of approximately 32%. On the other hand, the TiO2 coated samples exhibit the more enhanced absorption and photocurrent, compared to that of pure WO3/SnO2 IO, resulting in the high conversion efficiency. This points out that the proper coating of TiO2 layer on the WO3 photoelectrode can induce to the high dye adsorption as well as the suppressed charge recombination, granting the possibility of the challenging photoelectrode.

The Retardation Structure for Improvement of Photovoltaic Performances of Dye-Sensitized Solar Cell Under Low Illumination

The predominance for dye-sensitized solar cell (DSSC) is its application in low illumination. However, there are only a few studies to investigate the performance of DSSC under low illumination. In this study, we investigated DSSC's effect on photovoltaic performance under low illumination. The photoelectrode of DSSC is based on titanium dioxide–reduced graphene oxide (RGO)–indium gallium zinc oxide (IGZO) composited photoelectrode, which was fabricated through the hydro-thermal method, spin coating, and sputtering. According to our experiments, the improvement in photovoltaic conversion efficiency of DSSC achieved 69.57%, after introducing IGZO and RGO into the photoelectrode. Moreover, the enhancement of photovoltaic conversion efficiency under low illumination is due to the decrease in dark reaction, and the amount of the current is small under low illumination. Thus, in order to increase the photovoltaic conversion efficiency under low illumination, it is crucial to decrease the back reaction or dark reaction.

Synthesis of copper(II)–imidazole complex modified sandwich-type polyoxometalates for enhancing the power conversion efficiency in dye-sensitized solar cells

A inorganic–organic hybrids based on copper(II)–imidazole complex modified sandwich-type tungstoantimonite H6[Cu(im)4][Na2Cu3(H2O)3Cu(H2O)2(SbW9O33)2]·36H2O (1) (im = imidazole) was hydrothermally synthesized and characterized structurally by single crystal X-ray diffraction analysis. Its central band is composed of four Cu2+ and two Na+ forming a rare plane hexagon, and the sandwich-type anions [Na2Cu3(H2O)3Cu(H2O)2(SbW9O33)2]8- are further joined into a one-dimensional chain by a [Cu(im)4]2+ cation. The Kubelka-Munk function F and electrochemical cyclic voltammetry (CV) indicate that the energy level of 1 match well with the conduction band of TiO2, and compound 1 can act as an electron acceptor to accelerate the transfer of electrons. The UV–vis absorption Spectra of 1 has a wide range, and the absorption range of TiO2 can be extended to the visible region to improve the light absorption of TiO2 after doping with TiO2. The incorporation of 1 into TiO2 as the photoelectrodes of Dye-sensitized Solar Cells (DSSCs) improves the Jsc (the short circuit current density) and PCE (the power conversion efficiency) of DSSC, the DSSC assembled with 5%1@TiO2/P25 photoelectrodes has the best performance and its Jsc and PCE is 17.54 mA cm−2 and 7.71% respectively, the improvement of the efficiency is 26.8% compared with pure P25 (6.08%). In addition, electrochemical impedance spectroscopy and open circuit voltage decay show that 1 can promote electronic transfer, suppress charge recombination, and extend electronic lifetime.

Aerosol synthesis and luminescent properties of CaAl2O4:Eu2+, Nd3+ down-conversion phosphor particles for enhanced light harvesting of dye-sensitized solar cells

The dye molecules generally used in the photoelectrodes of dye-sensitized solar cells (DSSCs) are mostly effective for harvesting visible light. However, the ultraviolet (UV) light component of sunlight is not effectively harvested by these dye molecules. Thus, for inherent improvement of DSSC photovoltaic performance, effective UV light harvesting is necessary. To achieve this, we here attempt to synthesize down-converting phosphor particles, which can convert UV light to visible light. In this work, we fabricate CaAl2O4:Eu2+, Nd3+ phosphor particles using a simple and viable aerosol process in the gas phase; then, we investigate the role of these phosphor particles as a down-converting medium in DSSC photoelectrodes. The presence of Eu2+ and Nd3+ is observed in a CaAl2O4 matrix fabricated at a spray pyrolysis temperature of ∼850 °C with a subsequent H2 reduction temperature of ∼1120 °C. This finding indicates that those conditions are optimized for formation of these components with the strongest emission spectrum peak at ∼440 nm, corresponding to blue light. To examine the effect of the CaAl2O4:Eu2+, Nd3+ phosphor particles on the DSSC photovoltaic performance, various amounts of CaAl2O4:Eu2+, Nd3+ phosphor particles are added to the TiO2 matrixes in the DSSC photoelectrodes. Hence, the short-circuit current density and power conversion efficiency are found to increase with increasing CaAl2O4:Eu2+, Nd3+ phosphor particle content (≤5 wt%) in the TiO2 matrix. This suggests that addition of a critical amount of CaAl2O4:Eu2+, Nd3+ phosphor particles can enhance the DSSC light harvesting efficiency by effectively down-converting UV light from irradiating sunlight into additional visible light.

Sulfuric acid treatment of ZnO photoelectrode for photovoltaic improvement in dye-sensitized solar cell

Chemical wet treatment of ZnO films using the diluted sulfuric acid for dye-sensitized solar cell application was performed. The ZnO films were prepared from commercial ZnO nanoparticles using screen printing method and annealed. The films were treated by dipping into diluted sulfuric acid for different treatment times. Morphology of the treated ZnO films shows the nanowire formation for long treatment time. The treated ZnO films were then used as photoelectrode of dye-sensitized solar cell. The power conversion efficiency is achieved to be maximal value for the dye-sensitized solar cell fabricated with the treated ZnO films. It reveals the higher than the dye-sensitized solar cell fabricated with the non-treated ZnO films. The enhancement is due to the increased open-circuit voltage, the increased fill factor, the increased shunt resistance, and the decreased charge transfer resistance. In addition, the effect of sulfuric acid treatment is found to improve the charge transfer behaviour due to the nanowire formation. Therefore, the sulfuric acid treatment of ZnO photoelectrode has potential to provide charge transfer rate for better dye-sensitized solar cell application.

Low-temperature ozone annealing for dye-sensitized solar cells

The process whereby the TiO2 photoelectrode of dye-sensitized solar cells (DSSCs) is manufactured requires an annealing temperature of 450 °C. However, these DSSCs, which contain a low-cost, lightweight, and flexible plastic substrate, limit the annealing temperature to a maximum of 150 °C. This led us to develop a low-temperature (∼150 °C) annealing technique to process the TiO2 photoelectrode. The proposed method, which employs O3 as reactant, is based on the fact that O3 is thermally decomposed at ∼150 °C to produce atomic oxygen (O) atoms, to which the TiO2 photoelectrode is then exposed during annealing. Measurement of the carbon contents remaining on the TiO2 photoelectrode using energy dispersive X-ray spectrometry indicated that the O atoms can remove the organic binders contained in TiO2 paste. In addition, measurement of the energy conversion efficiency indicated that O atoms also have the ability to enhance TiO2 interparticle connections. This simple method to supply O atoms may not only be useful for treating the TiO2 photoelectrode of DSSCs but also for other surface treatments that require the use of O atoms.

Inertial impaction and surface diffusion-assisted rapid dye molecule adsorption on TiO2 thin films for highly efficient dye-sensitized solar cells

An effective and versatile single-stage aerosol impactor was specially designed to rapidly coat the surface of TiO2 thin films with a controlled amount of dye molecules via inertial impaction and surface diffusion to speed-up the manufacturing process and enhance the photovoltaic performance of dye-sensitized solar cells (DSSCs). By theoretically determining the specific dimensions of the aerosol accelerating nozzle and experimentally controlling the mixing ratio between the sheath gas and dye aerosol flow rates in the single-stage aerosol impactor, the speed and quality of dye adsorption on the TiO2 thin films of the photoelectrodes could be systematically assessed in terms of the photovoltaic performance of the DSSCs, including open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency (PCE). It was found that the aerosol impactor-assisted dye coating method developed in this study significantly reduced the duration of dye adsorption (aerosol coating duration = 20–60 min) and increased the PCE of the DSSCs to 7.28%. Using this methodology, dye-coating was ∼20 times faster and the fabricated device has 23% higher PCE compared to the DSSC fabricated by the conventional dip coating method (dip-coating duration = 1200 min, PCE = 5.92%). These results proved that the single-stage aerosol impactor designed in this study is a very effective and versatile device for rapidly coating the surface of TiO2 thin films with dye molecules using sufficient inertial impaction, which enables the introduced dye molecules to infiltrate and quickly adsorb on the surface of TiO2 nanoparticles accumulated in the DSSC photoelectrodes.

Photocharging and Band Gap Narrowing Effects on the Performance of Plasmonic Photoelectrodes in Dye-Sensitized Solar Cells.

The incorporation of plasmonic nanostructures in active electrodes has become one of the most attractive ways to enhance the photoconversion efficiency (PCE) of dye-sensitized solar cells (DSSCs). Although an enhancement of PCE because of the incorporation of plasmonic nanostructures of different sizes, either bare or coated, has been demonstrated, the fundamental mechanisms associated to such enhancement are still unclear. Besides, the photocurrent enhancement of plasmonic DSSCs is frequently associated to the strong surface plasmon resonance (SPR) absorption of metal nanoparticles. In this work, through oxygen K-edge soft X-ray absorption and emission spectroscopies of plasmonic electrodes and electrodynamical characterization of the fabricated cells, we demonstrate a band gap narrowing and photocharging effect on the plasmonic electrodes that definitely contribute to the PCE enhancement in plasmonic DSSCs. The incorporation of bare metal nanoparticles in active metal-oxide semiconductor electrodes such as TiO2 in optimum concentration causes an upward shift of its valence band edge, reducing its effective band gap energy and enhancing the short-circuit current of DSSCs. On the other hand, small perturbation-based stepped light-induced transient measurements of photovoltage and photocurrent of the operating DSSCs revealed an upward shift of quasi-Fermi level of photoelectrodes because of the photocharging effect induced by the incorporated metal nanoparticles. The upward shift of the quasi-Fermi level causes an increase in open-circuit voltage ( VOC), nullifying the effect of band gap reduction. The short-circuit photocurrent enhancement was controlled by the band gap narrowing, screening the SPR contribution. The results presented in this work not only clarify the contribution of SPR absorption in plasmonic DSSCs, but also highlight the importance of considering the corrections in the effective base voltage because of the quasi-Fermi level band shift during the estimation of the transport and recombination parameters of an assembled DSSC.

Low cost dye-sensitized solar cells based on zinc oxide and natural anthocyanin dye from Ardisia elliptica fruits

Natural dye is attractive to be used in dye sensitized solar cell (DSSC) as an alternative sensitizer. The main advantage of natural dye is its low cost production. Only simple procedure is needed to produce natural dyes where the pigments of plant parts like flowers, leaves, fruits and tubers were extracted using common solvents in the laboratory. In addition, the resources of natural dye are not only abundant, but also completely biodegradable. In this work, the natural dye was produced by extracting anthocyanin pigment from Ardisia elliptica fruits and called as Ardisia elliptica dye (AED). The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) level of AED was −6.06 eV and −3.88 eV respectively. AED is absorbed light in the green region with maximum absorption at a wavelength of 536.49 nm and the band gap was 2.31 eV which is acceptable as sensitizer for DSSC. Our photoelectrode of DSSC was fabricated by sensitizing zinc oxide (ZnO) nanoparticles layer with AED in different sensitizing duration (dye-loading time) and the best obtained photo conversion efficiency (PCE) was 0.04% which has been sensitized for 20 min.

The effect of boric acid concentration on the TiO2 compact layer by liquid-phase deposition for dye-sensitized solar cell

In this study, we prepared titanium oxide (TiO2) compact-layer thin films (thickness: 50 nm) on an indium tin oxide (ITO)/glass substrate by liquid-phase deposition (LPD) for the dye-sensitized solar cell (DSSC). We used a deposition solution of ammonium hexafluoro-titanate and boric acid (H3BO3) for the TiO2 film. We varied the concentration of H3BO3 from 0.4 to 0.7 M to control the deposition rate, surface roughness, and refractive index of the TiO2 film. Based on the results of X-ray diffraction and transmission electron microscopy, the TiO2 films all possessed the polycrystalline feature with (101), (004), (200), (105), and (211) planes. After the LPD deposition, we can observe that the formation of the transition-layer existed in the TiO2 film. The transition-layer is analyzed as In and Sn co-doped TiO2 film, which is caused by the diffusions of In3+ and Sn4+ ions from the ITO substrate. From the depth profiles of X-ray photoelectron spectroscopy, the thickness of the transition-layer increased with a decrease of the boric acid concentration. At the optimum H3BO3 concentration of 0.5 M, we obtained the following photovoltaic properties: a short circuit current density (Jsc) of 11.41 mA/cm2, an open circuit voltage (Voc) of 0.73 V, a fill factor (ff) of 0.63, and an efficiency (η) of 5.24%. The LPD-TiO2 compact-layer between the ITO and the DSSC photo-electrode can reduce the number of carrier recombinations and improve transmittance in the visible light region. The TiO2 compact-layer prevents electron transport to the electrolyte and results in a higher Jsc. Moreover, the LPD-TiO2 compact-layer can enhance interface adhesion and improve the series resistance.

Performance Evaluation of Titanate Nanotubes and Nanoribbons Deposited by Electrophoresis in Photoelectrodes of Dye-Sensitized Solar Cells

Nanoparticles of TiO2 have been the main semiconductor applied in Dye-sensitized solar cells (DSSCs). In this work, titanate nanotubes (NaTiNT) and nanoribbons, were obtained by the hydrothermal method from TiO2 anatase. These materials were deposited on conductive substrate by electrophoresis, with and without thermal treatment, sensitized by ruthenium-based dye and used as work electrode. Exposing those photovoltaic devices to visible radiation, with films before thermal treatment, a short-circuit current density (JSC) of 0.0012 mA/cm2 was observed for the cell with NaTiNT, a current density of 0.0398 mA/cm2 for the cell with Nanoribbons, and a current density of 0.4028 mA/cm2 for the cell with TiO2 as electrode. After thermal treatment, a short-circuit current density of 0.4269 mA/cm2 was observed for the cell with NaTiNT, a current density of 0.0765 mA/cm2 for the Nanoribbons cell, and, finally, a current density of 0.3310 mA/cm2 for the cell with TiO2 as electrode. The new morphological, structural and optical characteristics of these nanoparticles may contribute for the development and research of new generation photovoltaic devices.

A Barrier Structure for Photoelectrode of Dye-Sensitized Solar Cell for Enhancing Efficiency

In this letter, the indium–gallium–zinc oxide (IGZO) had been applied to the photoelectrode for reducing dark reaction. According to the experimental results, the IGZO film formed an energy barrier to retard the recombination between photo-generated electron in active layer and hole ( $I_{3}^{-}$ ) in electrolyte. It contributes an enhancement of electron lifetime, decrease in dark reaction, and improvement in the short-circuit current density ( $J_{\text {SC}}$ ). Consequently, the photovoltaic conversion efficiency of dye-sensitized solar cell is enhanced from 3.34% to 5.47%. This enhancement has the potential to expand an electron device of photocatalyst.

Different effects of Zn and Cu ions incorporated on TiO2 photoelectrodes on the back electron transfer in solar cells

ABSTRACTZinc and copper ions were incorporated on the surface of TiO2 films via a dipping process, and the resulting films were used as the photoelectrodes of dye-sensitized solar cells (DSSCs). The DSSC with Zn2+(30)-TiO2/FTO electrode, prepared by soaking bare TiO2/FTO in a zinc nitrate solution for 30 min, showed an improvement in power conversion efficiency, due to an enhancement in both open circuit voltage (Voc) and short circuit current (Jsc), compared to those of reference cell with bare TiO2/FTO. It was revealed that the Zn2+ incorporation on the TiO2 surface led to a retardation of the back electron transfer, inducing a prolonged electron lifetime of photo-injected electrons, and thereby increasing the Voc and Jsc. On the contrary, the back electron transfer was scarcely delayed in the device with Zn2+(30)-TiO2/FTO electrode.

Enhanced efficiency in dye-sensitized solar cells with La(OH)3:Yb3+/Er3+ and large particles scatting layer hybrid double photoanodes

A double-layer composite film (DLCF) that consists of upconversion composite La(OH)3:Er3+/Yb3++P25 (UC + P25) as underlayer and large TiO2 spheres (LS-TiO2) as overlayer is designed as the photoelectrode of dye-sensitized solar cells (DSSCs). The upconversion luminescent material La(OH)3:Er3+/Yb3+ can convert near-infrared region to visible light to improve the light absorption, and LS-TiO2 has been used as light-scattering layer to increase the optical length in the film and enhance light harvesting. The DLCF with lower absorbed dye achieved the highest conversion efficiency due to the synergistic effect of the upconversion luminescent layer and the light-scattering layer, and with an optimum mixing ratio, a conversion efficiency of 9.24% is attained, which is a significant improvement of 68.3% compared with the pure P25 film photoelectrode.

Facile synthesis of chrysanthemum flowers-like TiO2 hierarchical microstructures assembled by nanotube for high performance dye-sensitized solar cells

Abstract Chrysanthemum flowers-like TiO2 hierarchical microstructures assembled by nanotube are synthesized by a two-step hydrothermal route. The final TiO2 hierarchical microstructures are applied as a scattering layer on top of a transparent nanocrystalline TiO2 film, serving as the photoelectrode of dye-sensitized solar cells (DSSCs). In addition to efficient light scattering, the hierarchical microstructures provide a large surface area (105.4 m2/g) for higher dye loading and nanotube primary structure also provide a straight path for the electron fast transport. This multi functioning suggests that chrysanthemum flowers-like TiO2 hierarchical microstructures may be good scatter materials in DSSCs. A high efficiency of 7.71% is achieved for using the as-synthesized hierarchical microstructures as scattering layer, which is 21.8% higher than that of commercial P25 photoanode (6.33%) with the similar thickness.

Tuning Anatase Surface Reactivity toward Carboxylic Acid Anchor Groups.

The effect of different post-treatments on TiO2 anatase surface reactivity was investigated in order to obtain the best techniques for enhancing anatase performance in diverse applications, e.g., in photocatalysis and especially as photoelectrodes for dye-sensitized solar cells (DSSCs). Different post-treatments of compact anodic anatase TiO2 were compared, including O2 plasma, UV irradiation, immersion in H2O2, vapor thermal treatment, and post-anodization, evaluating the increase of the amount of OH reactive groups on the surface and removal of surface contamination. In XPS spectra, the increase of OH groups is evident by the O 1s peak at higher binding energy. ToF-SIMS principal component analysis demonstrated that treatments performed in aqueous media led to a cleaner surface, with substantial removal of electrolyte residues. Stearic acid and the organic dye N719 were adsorbed to the differently post-treated anatase, and adsorption was evaluated by contact angle and dye desorption measurements. A higher loading with molecules containing carboxylic acid functionalities was confirmed by both techniques on the treated samples. The post-treatments that presented the highest amounts of dye were used to prepare photoelectrodes, and these were tested in DSSCs where the efficiency values doubled in comparison with the non-post-treated electrode.

M(Al,Ni)-TiO2-Based Photoanode for Photoelectrochemical Solar Cells

Abstract This study presents the incorporation of Al and Ni cations onto the surface of TiO2 nanoparticles used as photoelectrode in dye sensitized solar cells (DSSCs). The incorporation of these cations was performed using the chemical bath deposition (CBD) technique. This process was applied up to three times to evaluate the semiconductors’ properties with respect to the amount of Al and Ni. The M(Al,Ni)-TiO2-based semiconductors were widely characterized using techniques such as X-ray fluorescence, X-ray diffraction, Raman spectroscopy, UV-Vis spectroscopy and X-ray photoelectron spectroscopy. The presence of (hydr)oxide species of Al(III) and Ni(II) was confirmed and anatase was the predominant crystalline phase obtained. Moreover, for both elements, a decrease in the band gap energy was observed, this being more pronounced after the incorporation of Ni. Furthermore, the use of the M(Al,Ni)-TiO2-based semiconductors as photoelectrodes in DSSCs led to an increase in the open-circuit voltage of up to 22% and 10% for the incorporation of Al and Ni, respectively. This increase can be reasonably explained by the negative shift of the flat band potential of the photoelectrodes. EIS measurements were performed to study the electron transport kinetics in the photoelectrode and the internal resistance in the DSSCs to understand the photocurrent density values obtained.

Characterization of LPD-TiO2 compact layer in ZnO nano-rods photoelectrode for dye-sensitized solar cell

A titanium oxide (TiO2) compact layer was used to enhance the performance of a dye-sensitized solar cell (DSSC) by reducing the electrical loss from recombination at the indium tin oxide (ITO)/electrolyte interface and by improving the electrical contact between ITO and the zinc oxide (ZnO) nano-rod photoelectrode. The TiO2 compact layer was deposited on ITO glass using the liquid phase deposition (LPD) method. DSSCs fabricated with and without the LPD-TiO2 compact layer were compared. In addition, various thicknesses of the LPD-TiO2 compact layer were evaluated. The light-to-electricity conversion efficiency of the DSSC increased from 0.43 to 0.75% by incorporating the LPD-TiO2 compact layer. Experimental results demonstrated that the LPD method is a promising alternative to the conventional TiO2 compact layer technology for the production of high-performance DSSCs.

Highly efficient SiO2/TiO2 composite photoelectrodes for dye-sensitized solar cells

A composite SiO2/TiO2 photoelectrode (PE) architecture for incorporating in dye-sensitized solar cells (DSC) was developed aiming to increase the electron mobility, the specific surface area and the transparency. The developed PE is made of a mesoporous SiO2 scaffold layer covered by a conformal TiO2 film deposited by atomic layer deposition (ALD). The shrinking core model was used to predict the minimum pulse time required for the complete coverage of the inner SiO2 scaffold surface area (ca. 160m2g−1). The TiO2 film thickness proved to be related to two DSC operation regimes: transport limited regime (Deff∝ TiO2 thickness, where Deff is the electron effective diffusivity) and a recombination limited regime (Deff constant); in the latter regime, the minimum recombination rate constant, kr, resulted in maximum DSC performance. DSCs based on the new PE coated with an optimized TiO2 film thickness (3.3nm, 150 ALD cycles) exhibited an average of 11% higher energy conversion efficiency than the standard devices, η=9.20% vs. η=8.25% and 10% more transmittance in the visible range. To the best of the authors’ knowledge this is the best reported DSC efficiency using a SiO2/TiO2 architecture. The superior performance exhibited by the new PE was ascribed to: higher surface area and lower electron recombination. The increased recombination resistance was attributed to lower morphological defects and better dye coverage of the TiO2 layer. This work shows that an ALD deposited TiO2 film ranging from 3 to 4nm in thickness is suitable for the dye adsorption and electron transport; when applied over a large surface area scaffold, the TiO2 nanolayer displayed the same transport abilities as reference TiO2 mesoporous films. The proposed PE opens the doors to new architectures and the use of new semiconductors with better properties concerning electronic mobility, conduction band energy level, transparency and recombination.