Dye-sensitized solar cells (DSSCs) suffer from efficiency limitations due to interfacial charge recombination at the TiO₂/dye/electrolyte interface. In this study, aminopropyltrimethoxysilane (APS) was introduced onto nanoporous TiO₂ photoelectrodes via a dip-coating process with controlled coating times to investigate the effect of silanization time on interfacial charge transport behavior. Unlike concentration-driven structural modification, this work focuses on the evolution of the APS-modified interface governed by reaction time. The DSSC with 30 min APS treatment exhibited the highest power conversion efficiency of 5.34%, representing a 19% enhancement compared to the untreated device (4.49%), mainly due to increased short-circuit current density and open-circuit voltage. However, prolonged coating times (2 h and 24 h) resulted in a significant decrease in photocurrent density, leading to reduced device performance despite partial improvement in recombination resistance. These results are attributed to the time-dependent evolution of the APS interfacial layer. At moderate coating time, APS provides effective surface functionalization, enhancing dye adsorption and suppressing interfacial recombination. In contrast, prolonged coating is expected to induce increased surface coverage and silane condensation, which can hinder electron injection and increase charge transport resistance. Therefore, the photovoltaic performance is governed by a trade-off between recombination suppression and charge injection efficiency, controlled by the silanization time. This study highlights the critical role of interfacial reaction kinetics in determining charge transport behavior and provides an effective strategy for optimizing DSSC performance through time-dependent interface engineering.

Dye adsorption is one of the most time-consuming processes in the fabrication of dye-sensitized solar cells (DSSCs), typically requiring approximately 24 h at room temperature. In this study, the effect of adsorption temperature and time on photovoltaic performance of DSSCs was investigated in order to reduce processing time and improve device productivity. Nanoporous TiO₂ photoelectrodes were immersed in N719 dye solution at 60°C for 3 h, 10 h, 17 h, and 24 h, and their performance was compared with that of cells sensitized at room temperature for 24 h. Photovoltaic characterization under AM 1.5 illumination showed that DSSCs sensitized at 60°C exhibited improved performance compared to those sensitized at room temperature. The device sensitized at 60°C for 3 h showed comparable or higher conversion efficiency than the reference cell sensitized for 24 h at room temperature. The improvement in device performance is attributed to enhanced dye adsorption kinetics resulting from increased reaction rate between the carboxyl groups of N719 dye molecules and hydroxyl groups on the TiO₂ surface. Electrochemical impedance spectroscopy analysis revealed reduced recombination resistance at the TiO₂/dye/electrolyte interface for cells sensitized at elevated temperature. UV–Vis absorption analysis confirmed increased dye loading on the TiO₂ surface for the 60°C condition. These results demonstrate that elevated temperature dye adsorption significantly reduces processing time while maintaining photovoltaic performance, providing an effective strategy for improving manufacturing efficiency of DSSCs.

Raman spectra of a-C:H thin films deposited with an unbalanced magnetron sputtering system showed that the G peak shifted to a higher wavenumber as the target power density increased and ID/IG ratio increased from 0.902 to 1.012. Moreover, the transmittance of a-C:H films fabricated at 60 nm tended to decrease with increasing target power density; at 550 nm in the visible light region, the transmittance decreased from 69% to 58%. The rms surface roughness values of the a-C:H thin films decreased with increasing target power density, and varied from 1.11 nm to 0.71 nm. In order to achieve efficient light trapping, the light scattering at the rough interface must be enhanced. Consequently, the surface roughness of the thin film will decrease with the target power density. Further, the refractive index and reflectivity of the a-C:H thin films increased with increasing target power density; however, the Brewster angle decreased with the target power density. Hence, dye-sensitized solar cells using an a-C:H antireflective coating increased the CE, VOC, and JSC by approximately 8.6%, 5.5%, and 4.5%, respectively.

In this study, e-beam equipment was used to form silver nanoparticles on thin films of TiO₂ to increase the efficiency of dye-sensitized solar cells and improve the annealing process. TiO₂ thin films with nanoparticle photoelectrodes were fabricated in individual units for use in dye-sensitized solar cells. The characteristics of dye-sensitized solar cells were compared to those of the prepared TiO₂ photoelectrode with and without nanoparticles. The dye-sensitized solar cells with silver nanoparticles showed a significant increase in the electric current density compared with the pure TiO₂ dye-sensitized solar cell and improved the solar conversion efficiency to 27.89%. The increased density of electric current increased the extent of light absorption of the dye owing to the plasmon resonance of the nanoparticles at the local surfaces. This phenomenon led to increased light scattering, which in turn increased the current density of the dye-sensitized solar cells and improved the solar conversion efficiency.

DSSCs (dye-sensitized solar cells) based on TiO₂/SiO₂ multi layer AR (anti-reflection) coating on the outer glass FTO (fluorine-doped tin oxide) substrate are investigated. We have coated an AR layer on the surface of a DSSCs device by using an IAD (ion beam-assisted deposition) system and investigated the effects of the AR layer by measuring photovoltaic performance. Compared to the pure FTO substrate, the multi layer AR coating increased the total transmittance from 67.4 to 72.9% at 530 nm of wavelength. The main enhancement of solar conversion efficiency is attributed to the reduction of light reflection at the FTO substrate surface. This leads to the increase of Jsc and the efficiency improvement of DSSCs.

A novel heteroleptic ruthenium(II) complex bearing a 4-picolinic acid unit as anchoring ligands (trans-dithiocyanato bis(4-picolinic acid)ruthenium(II) (trans-H1)) was synthesized and its chemical structure was identified by 1H-NMR, FT-IR and mass spectroscopy. The optical, thermal, electrochemical and dye adsorption properties of trans-H1 dye were investigated and compared with those of the gold standard ruthenium complex, Ru(4,4``-dicarboxy-2,2``-bipyridine)2cis(NCS)2 (N3). DSSCs based on trans-H1 dyes were examined under the illumination of AM 1.5 G, 100 mWcm-2 and exhibited typical photovoltaic properties with an open-circuit voltage (VOC) of 0.46 V, a short-circuit current (JSC) of 4.10 mA·cm-2, a fill factor (FF) of 60.4%, and a conversion efficiency (PCE) of 1.14%.

Rhodamine B (RhB) was utilized as a dye sensitizer for dye-sensitized solar cells (DSSCs) and its photovoltaic property was examined under the illumination of AM 1.5 G, 100 mWcm-2. DSSCs based on RhBexhibited typical photovoltaic properties with an open-circuit voltage (VOC) of 0.34 V, a short-circuit current (JSC) of 1.55 mA·cm-2, a fill factor (FF) of 50%, and a conversion efficiency (PCE) of 0.26%. In order to further improve the photovoltaic properties of RhB-based DSSCs, the effect of (i) incorporating a strong electron-donating NCS unit into the RhB molecular backbone, (ii) combining a bis-negatively charged zinc complex anion (Zn-dmit2, dmit=di-mercapto-dithiol-thione) with the amine cation of RhB, (iii) co-adsorbing RhB dyes with chenodeoxycholic acid (CDCA) molecules onto porous TiO2 electrodes, was investigated and discussed.

In this study, we propose Ti hole pattern structure on the transparent conductive oxide (TCO) lessdye-sensitized solar cells (DSSCs) using the lift-off process to improve the low light transmittance and lowefficiency caused by opaque Ti electrode. The formation of Ti hole patterns make it possible to move the dyeadsorption and electrolyte. The DSSCs with Ti hole patterns showed a higher photoelectric conversion efficiency(PCE) than those with general structure by 11.1%. As a result, The Ti hole pattern structure can be improved toincrease the light absorption of the dyes and PCE of the TCO-less DSSCs is also increased.

Stainless steel (SS) mesh was used to fabricate photo electrode for flexible dye-seisitzed solar cells(DSSCs) in order to evaluate them as replacements for more expensive transparent conductive oxide(TCO). We fabricated the DSSCs with new type of photo electrode, which consisted of flexible SS mesh coated with 100 nm thickness titanium (Ti) protective layer deposited using electron-beam deposition system. SS mesh DSSCs with protective layer showed higher efficiency than those without a protective layer. The best cell property in the present study showed the open circuit voltage (Voc) of 0.608 V, short-circuit current density (Jsc) of 5.73 mA cm-2, fill factor (FF) of 65.13%, and efficiency (η) of 2.44%. Compared with SS mesh based on DSSCs (1.66%), solar conversion of SS mesh based on DSSCs with protective layer improved about 47%.

In this work, in order to manufacture the photoelectrode of dye-sensitized solar cells, thedifferent anatase TiO2 paste was prepared by simple route using hydrothermal method. In comparisonwith the traditional preparing process, the hydrothermally synthesized TiO2 gel was used to make pastedirectly. Thus, the making process was simplified and the solar conversion efficiency was improved. Incomparison with 5.34% solar energy efficiency of HP-1 photoelectrode, the 6.23% efficiency of HDP-1electrode was improved by 16.67%. This is because hydrothermally synthesized TiO2 gel was used tomake paste directly, the dispersibility between TiO2 particles was improved and get the smoothernetwork, leading to the charge transport ability of the electron generated in dye molecular was improved. Further, HDP-2 photoelectrode delivered the best results with Voc (open circuit voltage), Jsc (shortcircuit current density) FF (fill factor) and η(solar conversion efficiency) were 0.695 V, 15.81 mA cm-2,61.48% and 6.80%, respectively. In comparison with 5.34% of HP-1 photoelectrode, it was improved by27.34%.

In this study, a transparent conductive oxide (TCO)-less dye-sensitized solar cells (DSSCs)was fabricated by using titanium (Ti) electrode to replace the Fluorine-doped tin oxide (FTO) for thereduction of manufacturing cost. Ti film was formed by electron beam evaporation method and the resultsshowed the sheet resistance of Ti electrodes with a thikness of 500 nm similar to FTO. In case of powerconversion efficiency (PCE), a DSSC with Ti electrodes showed a lower value than that with FTO by0.38%. For the investigation of the difference, the DSSCs were measured and analyzed by usingelectrochemical impedance analyzer (EIS).

In this work, according to temperature and time of hydrothermal synthesis, the electrochemical properties of TiIO2 particle using TTIP based on thanging temperature and time in the hydrothermal synthesis were analyzed and optimized temperature and time were derived. When hydrothermal synthesis were analyzed and optimized temperature and time were derived. When hydrothermal synthesis temperature and time were 200℃ and 1 h, respectively. The fabricated DSSC delivered the best electrochemical properties. In that case, TiO2 particle size was 13.018 nm, electron transport time was 2.34×103s and recombination time was 4.01×102s. The lowest impedance of 13.52 Ω and Voc, Jsc, FF is 0.70 V, 11.50 mAcm2, 65.62%, respectively and corresponding efficiency of 5.34% was considered as the optimal.

In this paper, the low-temperature sintering of TiO2 is approached to solve the problem of high temperature sintering which decreases the interconnection between particles or between substrate and particle. TiO2 paste is prepared with Titanium (Ⅳ) isopropoxide as the precursor material and calcinate at different conditions (low temperature). In the results, since the changing of temperature and time of sintering, crystalline phase do not change and the intensities of anatase, rutile phase are higher. At 110℃, 7 h sintering condition, crystalline size of anatase and rutile phase are the smallest which are 13.07 and 17.47 nm, respectively. In addition, the highest zeta potential is about 32.77 mV and the repulsive force increases thus leading to the best of the dispersion characteristics between TiO2 particles. Futhermore, DSSCs at that condition exhibits the highest efficiency with the values of Voc, Jsc, FF and η are 0.69 V, 8.60 mA cm-2, 67.93% and 4.06%, respectively.

In this Paper, we have developed1 a low temperature process to make two type of Paste by using TIO2 nanoprticles(P25). The interconnections between substrate and TiO2 films or link between particles of free-binder Paste (FP1, FPZ, FP3) is very poor. Therefore, the Titanium(IV) isopropoxide was added to the TP paste to improve the interconnection. Electron transport time (Tt) and recombination time (Tr) are analyzed by IMPS (intensity-modulated photocurrent spectroscopy) and INIVS (Intensity-modulated photovltage spectroscopy). In the results, Tt of TP paste based DSSCs (about 4.3×10-3) is faster than other samples. Tt is Ionger from 2.7×10-2 s of FP2 to 3.0×10-2 s of TP. A solar conversion efficiency (DSSCs) of TP 15 3.54% for an incident solar energy of 100 mw cm-2(meanwhile, 2. 70% for DSSCs With FP2). The c아1versioIl efficiency is increased by 1.3 times.

Dye-sensitized solar cells (DSSCs) based on titanium dioxide (TiO2) have been extensively studied because of their promising low-cost alternatives to conventional semiconductor based solar cells. DSSCs consist of molecular dye at the interface between a liquid electrolyte and a mesoporous wide-bandgap semiconductor oxide. Most efforts for high conversion efficiencies have focused on dye and liquid electrolytes. However, interface engineering between dye and electrode is also important to reduce recombination and improve efficiency. In this work, for interface engineering, we deposited semiconducting ferroelectric BiFeO3 with bandgap of 2.8 eV on TiO2 nanoparticles and nanotubes. Photovoltaic properties of DSSCs were characterized as a function of thickness of BiFeO3. We showed that ferroelectric BiFeO3-coated TiO2 electrodes enable to increase overall efficiency of DSSCs, which was associated with efficient electron transport due to internal electric field originating from electric polarization. It was suggested that engineering the dye-TiO2 interface using ferroelectric materials as inorganic modifiers can be key parameter for enhanced photovoltaic performance of the cell.

The utilization of a fluoran leuco sensitizer, 2-anilino-6-dibutyl amino-3-methylfluoran (ODB-2), for dye-sensitized solar cells (DSSCs) was investigated through the examination of the adsorption of ODB-2 molecules onto the surfaces of porous titanium dioxide (titania, TiO2) films and the photovoltaic properties of ODB-2-based DSSCs. Despite of the absence of the specific anchoring groups with titania, ODB-2 dye molecules were spontaneously adsorbed onto the titania surfaces because the lactone ring in ODB-2 was opened and changed into the carboxylic acid (-COOH) by releasing protons from the surfaces (TiOH2 +) of titania, which consequently leads to the chemisorption reaction of ODB-2 molecules to the active sites of titania. DSSCs based on ODB-2 exhibited typical photovoltaic properties with an open-circuit voltage (VOC) of 0.19 V, a short-circuit current (JSC) of 0.30 mA·cm-2, a fill factor (FF) of 37%, and a conversion efficiency (PCE) of 0.02%.

We use UV(ultraviolet)-O3 treatment to increase the surface area and porosity of TiO2 films in dye-sensitized solar cells (DSSCs). After the UV-O3 treatment, surface area and porosity of the TiO2 films were increased, the increased porosity lead to amount of dye loading and solar conversion efficiency was improved. Field emission scanning electron microscopy images clearly showed that the nanocrystalline porosity of films were increased by UV-O3 treatment. The Brunauer, Emmett, and Teller surface area of the TiO2 films were increased from 0.71 cm2/g to 1.31 cm2/g by using UV-O3 treatment for 20 min. Also, UV-O3 treatment of TiO2 films significantly enhanced their solar conversion efficiency. The efficiency of the films without treatment was 4.9%, and was increased to 5.6% by UV-O3 treatment for 20 min. Therefore the process enhanced the solar conversion efficiency of DSSCs, and can be used to develop high sensitivity DSSCs.

The adsorption kinetic study of ruthenium complex, N3, onto nanoporous titanium dioxide (TiO2) photoanodes has been carried out by measuring dye uptake in-situ. Three simplified kinetic models including a pseudo first-order equation, pseudo second-order equation and intraparticle diffusion equation were chosen to follow the adsorption process. Kinetic parameters, rate constant, equilibrium adsorption capacities and related coefficient coefficients for each kinetic model were calculated and discussed. It was shown that the adsorption kinetics of N3 dye molecules onto porous TiO2 obeys pseudo second-order kinetics with chemisorption being the rate determining step. Additionally the heterogeneous surface and the pore size distribution of porous TiO2 adsorbents were also discussed.

Hybrid SiO2-TiO2 photoelectrode with different type of layers was investigated in dye-sensitized solar cells (DSSC). 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. So, thus, it becomes necessary to include a SiO2-TiO2 layer for increase light harvesting effect such that the lower photon conversion due to thin layer could be compensated. In this paper reports the use of transparent high surface area TiO2 layer and an additional SiO2-TiO2 layer, thus ensuring adequate light harvesting in these devices. The best solar conversion efficiency 6.6% under AM 1.5 was attained with a multi-layer structure using TiO2 layer/SiO2-TiO2 layer/TiO2 layer for the light harvesting and this had resulted to about 44% increase in photocurrent density of dye-sensitized solar cells.

In this work, electrochemical characteristics and optical transmittance of carbon nanotubes (CNTs) counter electrodes which had different amount of CNTs in CNTs slurries were analyzed. Two-step heat treatment processes were applied to achieve well-fabricated CNTs electrode. Three sets of CNTs electrodes and dye-sensitized solar cells (DSSCs) with CNTs counter electrodes were prepared. As the amount of CNTs increased, sheet resistance of CNTs electrode decreased. CNTs electrode with low sheet resistance had low electrochemical impedance and fast redox reaction. On the other hand, in case of CNTs counter electrode with low density of CNTs, performance of the dye-sensitized solar cell was improved due to its high optical transmittance. We found that the transmittance of CNTs counter electrode influence the performance of dye-sensitized solar cells.