Hierarchical Double‐Shell Nanostructures of TiO2 Nanosheets on SnO2 Hollow Spheres for High‐Efficiency,Solid‐State,Dye‐Sensitized Solar Cells

A high‐energy conversion efficiency of 8.2% at 100 mW cm^?2 is reported, one of the highest values for N719‐based, solid‐state, dye‐sensitized solar cells (ssDSSCs). The solar cells are based on hierarchical double‐shell nanostructures consisting of inner SnO₂ hollow spheres (SHS) surrounded by outer TiO₂ nanosheets (TNSs). Deposition of the TNS on the SHS outer surface is performed via solvothermal reactions in order to generate a double‐shell SHS@TNS nanostructure that provides a large surface area and suppresses recombination of photogenerated electrons. An organized mesoporous (OM)‐TiO₂ film with high porosity, large pores, and good interconnectivity is also prepared via a sol‐gel process using a poly(vinyl chloride)‐g‐poly(oxyethylene methacrylate) (PVC‐g‐POEM) graft copolymer template. This film is utilized as a matrix to disperse the double‐shell nanostructures. Such nanostructures provide good pore‐filling for solid polymer electrolytes, faster electron transfer, and enhanced light scattering, as confirmed by reflectance spectroscopy, incident photon‐to‐electron conversion efficiency (IPCE), and intensity‐modulated photocurrent spectroscopy (IMPS)/intensity‐modulated photovoltage spectroscopy (IMVS).     

Enhanced Performance of I2‐Free Solid‐State Dye‐Sensitized Solar Cells with Conductive Polymer up to 6.8%

An iodine‐free solid‐state dye‐sensitized solar cell (ssDSSC) is reported here, with 6.8% energy conversion efficiency—one of the highest yet reported for N719 dye—as a result of enhanced light harvesting from the increased transmittance of an organized mesoporous TiO₂ interfacial layer and the good hole conductivity of the solid‐state‐polymerized material. The organized mesoporous TiO₂ (OM‐TiO₂) interfacial layer is prepared on large‐area substrates by a sol‐gel process, and is confirmed by scanning electron microscopy (SEM) and grazing incidence small‐angle X‐ray scattering (GISAXS). A 550‐nm‐thick OM‐TiO₂ film coated on fluorine‐doped tin oxide (FTO) glass is highly transparent, resulting in transmittance increases of 8 and 4% compared to those of the bare FTO and conventional compact TiO₂ film on FTO, respectively. The high cell performance is achieved through careful control of the electrode/hole transport material (HTM) and nanocrystalline TiO₂/conductive glass interfaces, which affect the interfacial resistance of the cell. Furthermore, the transparent OM‐TiO₂ film, with its high porosity and good connectivity, exhibits improved cell performance due to increased transmittance in the visible light region, decreased interfacial resistance ( Ω ), and enhanced electron lifetime ( τ ). The cell performance also depends on the conductivity of HTMs, which indicates that both highly conductive HTM and the transparent OM‐TiO₂ film interface are crucial for obtaining high‐energy conversion efficiencies in I₂‐free ssDSSCs.     

Room‐Temperature Synthesis of Porous Nanoparticulate TiO2 Films for Flexible Dye‐Sensitized Solar Cells

A novel room‐temperature method for the preparation of porous TiO₂ films with high performance in dye‐sensitized solar cells (DSSCs) has been developed. In this method a small amount of Ti^IV tetraisopropoxide (TTIP) is added to an ethanolic paste of TiO₂ nanoparticles, where it hydrolyzes in situ and connects the TiO₂ particles to form a homogenous and mechanically stable film of up to 10 μm thickness without crack formation. Residual organics originating from the TTIP were removed by UV–ozone treatment of the films, leading to a remarkable improvement of the cell efficiency. Intensity‐modulated photocurrent/voltage spectroscopy (IMPS/IMVS) showed that the main effect of the UV–ozone treatment is to suppress the recombination of photogenerated electrons, thereby extending their lifetime. The efficiency was further increased by preheating the TiO₂ nanoparticles before the paste preparation to remove contaminants originating from the preparation process of the particles. Solar‐to‐electric energy conversion efficiencies of 4.00 and 3.27 % have been achieved for cells with conductive glass and plastic film substrates, respectively, under illumination with AM 1.5 (100 mW cm^–2) simulated sunlight.     

Honeycomb‐Like Organized TiO2 Photoanodes with Dual Pores for Solid‐State Dye‐Sensitized Solar Cells

A solid‐state dye‐sensitized solar cell (ssDSSC) with 7.4% efficiency at 100 mW/cm² is reported. This efficiency is one of the highest observed for N719 dye. High performance is achieved via a honeycomb‐like, organized mesoporous TiO₂ photoanode with dual pores, high porosity, good interconnectivity, and excellent light scattering properties. The TiO₂ photoanodes are prepared without any TiCl₄ treatment via a one‐step, direct self‐assembly of hydrophilically preformed TiO₂ nanocrystals and poly(vinyl chloride)‐g‐poly(oxyethylene methacrylate) (PVC‐g‐POEM) graft copolymer as a titania source and a structure‐directing agent, respectively. Upon controlling the secondary forces between the polymer/TiO₂ hybrid and the solvent by varying the amounts of HCl/H₂O mixture or toluene, honeycomb‐like structures are generated to improve light scattering properties. Such multifunctional nanostructures with dual pores provide good pore‐filling of solid polymer electrolyte with large volume, enhanced light harvesting and reduced charge recombination, as confirmed by reflectance spectroscopy, incident photon‐to‐electron conversion efficiency (IPCE), and electrochemical impedance spectroscopy (EIS) analysis.     

Enhancing the Performance of Solid‐State Dye‐Sensitized Solar Cells Using a Mesoporous Interfacial Titania Layer with a Bragg Stack

High efficiency dye‐sensitized solar cells (DSSCs) are fabricated with a heterostructured photoanode that consists of a 500‐nm‐thick organized mesoporous TiO₂ (om‐TiO₂) interfacial layer (IF layer), a 7 or 10‐μm thick nanocrystalline TiO₂ layer (NC layer), and a 2‐μm‐thick mesoporous Bragg stack (meso‐BS layer) as the bottom, middle and top layers, respectively. An om‐TiO₂ layer with a high porosity, transmittance, and interconnectivity is prepared via a sol‐gel process, in which a poly(vinyl chloride)‐g‐poly(oxyethylene methacrylate) (PVC‐g‐POEM) graft copolymer is used as a structure‐directing agent. The meso‐BS layer with large pores is prepared via alternating deposition of om‐TiO₂ and colloidal SiO₂ (col‐SiO₂) layers. Structure and optical properties (refractive index) of the om‐TiO₂ and meso‐BS layers are studied and the morphology of the heterostructured photoanode is characterized. DSSCs fabricated with the heterostructured IF/NC/BS photoanode and combined with a polymerized ionic liquid (PIL) exhibit an energy conversion efficiencies of 6.6% at 100 mW/cm², one of the highest reported for solid‐state DSSCs and much larger than cells prepared with only a IF/NC layer (6.0%) or a NC layer (4.5%). Improvements in energy conversion efficiency are attributed to the combination of improved light harvesting, decreased resistance at the electrode/electrolyte interface, and excellent electrolyte infiltration.     

An efficient titanium‐based photoanode for dye‐sensitized solar cell under back‐side illumination

Pretreatment of H₂O₂ is performed on titanium (Ti) foil as an efficient photoanode substrate for dye‐sensitized solar cell (DSSC). The H₂O₂‐treated Ti shows high surface area because of the formation of networked TiO₂ nanosheets, which enhances electrical contact between screen‐printed TiO₂ nanoparticles and Ti foil. Electron transfer on the photoanode is improved, as identified by reduced charge transfer resistance and improved electron transport properties. Compared with DSSC based on non‐treated Ti photoanode, DSSC with this H₂O₂‐treated Ti photoanode exhibits remarkable increases in short‐circuit current density (from 8.55 to 14.38 mA/cm²) and energy conversion efficiency (from 4.68 to 7.10%) under AM1.5 back‐side illumination. Copyright © 2011 John Wiley & Sons, Ltd.     

High Efficiency Solid‐State Dye‐Sensitized Solar Cells Assembled with Hierarchical Anatase Pine Tree‐like TiO2 Nanotubes

A facile and effective method to prepare hierarchical pine tree‐like TiO₂ nanotube (PTT) arrays with an anatase phase directly grown on a transparent conducting oxide substrate via a one‐step hydrothermal reaction. The PTT arrays consist of a vertically oriented long nanotube (NT) stem and a large number of short nanorod (NR) branches. Various PTT morphologies are obtained by adjusting the water/diethylene glycol ratio. The diameter of the NTs and the size of the NR branches decreases from 300 to100 nm and from 430 to 230 nm, respectively, with increasing water content. The length of the PTT arrays could be increased up to 19 μm to significantly improve the charge transport and specific surface area. The solid‐state dye‐sensitized solar cells (ssDSSC) assembled with the 19 μm long PTT arrays exhibit an outstanding energy‐conversion efficiency of 8.0% at 100 mW/cm², which is two‐fold higher than that of commercially available paste (4.0%) and one of the highest values obtained for N719 dye‐based ssDSSCs. The high performance is attributed to the larger surface area, improved electron transport, and reduced electrolyte/electrode interfacial resistance, resulting from the one‐dimensional, well‐aligned structure with a high porosity and large pores.     

A Near‐Infrared cis‐Configured Squaraine Co‐Sensitizer for High‐Efficiency Dye‐Sensitized Solar Cells

A cis‐configured squaraine dye (HSQ1), synthesized by incorporation of a strongly electron‐withdrawing dicyanovinyl group into the central squaric acid moiety, is employed in dye‐sensitized solar cells (DSCs). In solution, HSQ1 displays an intense absorption in the near‐infrared region with a maximum at 686 nm and when the dye is adsorbed on a TiO₂ surface, the absorption spectrum broadens in both the blue and the near‐infrared regions, which is favorable for efficient light harvesting over a broad wavelength range. A solar cell sensitized with HSQ1 shows a broader incident photon‐to‐current conversion efficiency (IPCE) spectrum (from 400 to 800 nm) and a higher IPCE in the long‐wavelength region (71% at 700 nm) than a cell sensitized with squaraine dye SQ1. Furthermore, a solar cell co‐sensitized with HSQ1 and N3 dye shows remarkably improved short‐circuit current density and open‐circuit voltage compared to those of a DSC based on N3 alone and fabricated under the same conditions. The energy‐conversion efficiency of the co‐sensitized DSC is 8.14%, which is the highest reported efficiency for a squaraine dye–based co‐sensitized DSC without using Al₂O₃ layer.     

Electrically Programmable Bistable Capacitor for High‐Frequency Applications Based on Charge Storage at the (Ba,Sr)TiO3/Al2O3 Interface

Hysteresis is induced in paraelectric (Ba,Sr)TiO₃ (BST) thin‐film capacitors by inserting an Al₂O₃ barrier layer of a few nanometers in thickness between the BST layer and the electrode. The observed hysteresis is explained by ambipolar charge carrier injection through the Al₂O₃ layer and charge storage at the BST/Al₂O₃ interface. The magnitude of the hysteresis can be directly adjusted by manipulating the thickness ratio between BST and Al₂O₃. Taking into account the low loss of (Ba,Sr)TiO₃ capacitors, the observed switching and retention characteristics are suitable for application as non‐volatile programmable high‐frequency devices, e.g., in radio‐frequency identification.     

Enhanced Performance of P2‐Na0.66(Mn0.54Co0.13Ni0.13)O2 Cathode for Sodium‐Ion Batteries by Ultrathin Metal Oxide Coatings via Atomic Layer Deposition

Sodium‐ion batteries are widely considered as promising energy storage systems for large‐scale applications, but their relatively low energy density hinders further practical applications. Developing high‐voltage cathode materials is an effective approach to increase the overall energy density of sodium‐ion batteries. When cut‐off voltage is elevated over 4.3 V, however, the cathode becomes extremely unstable due to structural transformations as well as metal dissolution into the electrolytes. In this work, the cyclic stability of P2‐Na_0.66(Mn_0.54Co_0.13Ni_0.13)O₂ (MCN) electrode at a cut‐off voltage of 4.5 V is successfully improved by using ultrathin metal oxide surface coatings (Al₂O₃, ZrO₂, and TiO₂) deposited by an atomic layer deposition technique. The MCN electrode coated with the Al₂O₃ layer exhibits higher capacity retention among the MCN electrodes. Moreover, the rate performance of the MCN electrode is greatly improved by the metal oxide coatings in the order of TiO₂ < Al₂O₃ < ZrO₂, due to increased fracture toughness and electrical conductivity of the metal oxide coating layers. A ZrO₂‐coated MCN electrode shows a discharge capacity of 83 mAh g^?1 at 2.4 A g^?1, in comparison to 61 mAh g^?1 for a pristine MCN electrode. Cyclic voltammetry and electrochemical impedance analysis disclose the reduced charge transfer resistance from 1421 to 760.2 Ω after cycles, suggesting that the metal oxide coating layer can effectively minimize the undesirable phase transition, buffer inherent stress and strain between the binder, cathode, and current collector, and avoid volumetric changes, thus increasing the cyclic stability of the MCN electrode.     

Thin Al2O3 passivated boron emitter of n‐type bifacial c‐Si solar cells with industrial process

We have presented thin Al₂O₃ (~4 nm) with SiN_x:H capped (~75 nm) films to effectively passivate the boron‐doped p⁺ emitter surfaces of the n‐type bifacial c‐Si solar cells with BBr₃ diffusion emitter and phosphorus ion‐implanted back surface field. The thin Al₂O₃ capped with SiN_x:H structure not only possesses the excellent field effect and chemical passivation, but also establishes a simple cell structure fully compatible with the existing production lines and processes for the low‐cost n‐type bifacial c‐Si solar cell industrialization. We have successfully achieved the large area (238.95 cm²) high efficiency of 20.89% (front) and 18.45% (rear) n‐type bifacial c‐Si solar cells by optimizing the peak sintering temperature and fine finger double printing technology. We have further shown that the conversion efficiency of the n‐type bifacial c‐Si solar cells can be improved to be over 21.3% by taking a reasonable high emitter sheet resistance. Copyright © 2017 John Wiley & Sons, Ltd.     

Porous Ti4O7 Particles with Interconnected‐Pore Structure as a High‐Efficiency Polysulfide Mediator for Lithium–Sulfur Batteries

Multifunctional Ti₄O₇ particles with interconnected‐pore structure are designed and synthesized using porous poly(styrene‐b ‐2‐vinylpyridine) particles as a template. The particles can work efficiently as a sulfur‐host material for lithium–sulfur batteries. Specifically, the well‐defined porous Ti₄O₇ particles exhibit interconnected pores in the interior and have a high‐surface area of 592 m² g^?1; this shows the advantage of mesopores for encapsulating of sulfur and provides a polar surface for chemical binding with polysulfides to suppress their dissolution. Moreover, in order to improve the conductivity of the electrode, a thin layer of carbon is coated on the Ti₄O₇ surface without destroying its porous structure. The porous Ti₄O₇ and carbon‐coated Ti₄O₇ particles show significantly improved electrochemical performances as cathode materials for Li–S batteries as compared with those of TiO₂ particles.     

High‐efficiency black silicon interdigitated back contacted solar cells on p‐type and n‐type c‐Si substrates

This work demonstrates the high potential of Al₂O₃ passivated black silicon in high‐efficiency interdigitated back contacted (IBC) solar cells by reducing surface reflectance without jeopardizing surface passivation. Very low reflectance values, below 0.7% in the 300–1000 nm wavelength range, together with striking surface recombination velocities values of 17 and 5 cm/s on p‐type and n‐type crystalline silicon substrates, respectively, are reached. The simultaneous fulfillment of requirements, low reflectance and low surface recombination, paves the way for the fabrication of high‐efficiency IBC Si solar cells using black silicon at their front surface. Outstanding photovoltaic efficiencies over 22% have been achieved both in p‐type and n‐type 9‐cm² cells. 3D simulations suggest that efficiencies of up to 24% can be obtained in the future with minor modifications in the baseline fabrication process. Copyright © 2015 John Wiley & Sons, Ltd.     

Rationally Engineered Electrodes for a High‐Performance Solid‐State Cable‐Type Supercapacitor

Wire‐shaped electrodes for solid‐state cable‐type supercapacitors (SSCTS) with high device capacitance and ultrahigh rate capability are prepared by depositing poly(3,4‐ethylenedioxythiophene) onto self‐doped TiO₂ nanotubes (D‐TiO₂) aligned on Ti wire via a well‐controlled electrochemical process. The large surface area, short ion diffusion path, and high electrical conductivity of these rationally engineered electrodes all contribute to the energy storage performance of SSCTS. The cyclic voltammetric studies show the good energy storage ability of the SSCTS even at an ultrahigh scan rate of 1000 V s^?1, which reveals the excellent instantaneous power characteristics of the device. The capacitance of 1.1 V SSCTS obtained from the charge–discharge measurements is 208.36 µF cm^?1 at a discharge current of 100 µA cm^?1 and 152.36 µF cm^?1 at a discharge current of 2000 µA cm^?1, respectively, indicating the ultrahigh rate capability. Furthermore, the SSCTS shows superior cyclic stability during long‐term (20 000 cycles) cycling, and also maintains excellent performance when it is subjected to bending and succeeding straightening process.     

Increasing the Efficiency of Organic Dye‐Sensitized Solar Cells over 10.3% Using Locally Ordered Inverse Opal Nanostructures in the Photoelectrode

3D inverse opal (3D‐IO) oxides are very appealing nanostructures to be integrated into the photoelectrodes of dye‐sensitized solar cells (DSSCs). Due to their periodic interconnected pore network with a high pore volume fraction, they facilitate electrolyte infiltration and enhance light scattering. Nonetheless, preparing 3D‐IO structures directly on nonflat DSSC electrodes is challenging. Herein, 3D‐IO TiO₂ structures are prepared by templating with self‐assembled polymethyl methacrylate spheres on glass substrates, impregnation with a mixed TiO₂:SiO₂ precursor and calcination. The specific surface increases from 20.9 to 30.7 m² g^?1 after SiO₂ removal via etching, which leads to the formation of mesopores. The obtained nanostructures are scraped from the substrate, processed as a paste, and deposited on photoelectrodes containing a mesoporous TiO₂ layer. This procedure maintains locally the 3D‐IO order. When sensitized with the novel benzothiadiazole dye YKP‐88, DSSCs containing the modified photoelectrodes exhibit an efficiency of 10.35% versus 9.26% for the same devices with conventional photoelectrodes. Similarly, using the ruthenium dye N719 as sensitizer an efficiency increase from 5.31% to 6.23% is obtained. These improvements originate mainly from an increase in the photocurrent density, which is attributed to an enhanced dye loading obtained with the mesoporous 3D‐IO structures due to SiO₂ removal.     

New Family of Ruthenium‐Dye‐ Sensitized Nanocrystalline TiO2 Solar Cells with a High Solar‐Energy‐Conversion Efficiency

A new type of ruthenium complexes 6 – 8 with tridentate bipyridine–pyrazolate ancillary ligands has been synthesized in an attempt to elongate the π‐conjugated system as well as to increase the optical extinction coefficient, possible dye uptake on TiO₂, and photostability. Structural characterization, photophysical studies, and corresponding theoretical approaches have been made to ensure their fundamental basis. As for dye‐sensitized solar cell applications, it was found that 6 – 8 possess a larger dye uptake of 2.4 × 10^–7 mol cm^–2, 1.5 × 10^–7 mol cm^–2, and 1.3 × 10^–7 mol cm^–2, respectively, on TiO₂ than that of the commercial N3 dye (1.1 × 10^–7 mol cm^–2). Compound 8 works as a highly efficient photosensitizer for the dye‐sensitized nanocrystalline TiO₂ solar cell, producing a 5.65 % solar‐light‐to‐electricity conversion efficiency (compare with 6.01 % for N3 in this study), a short‐circuit current density of 15.6 mA cm^–2, an open‐circuit photovoltage of 0.64 V, and a fill factor of 0.57 under standard AM 1.5 irradiation (100 mW cm^–2). These, in combination with its superior thermal and light‐soaking stability, lead to the conclusion that the concomitant tridentate binding properties offered by the bipyridine‐pyrazolate ligand render a more stable complexation, such that extended life spans of DSSCs may be expected.     

Effectively Utilizing NIR Light Using Direct Electron Injection from Up‐Conversion Nanoparticles to the TiO2 Photoanode in Dye‐Sensitized Solar Cells

TiO₂/NaYF₄:Yb³⁺,Er³⁺ nano‐heterostructures are prepared in situ on the TiO₂ photoanode of dye‐sensitized solar cells (DSCs). Transmission electron microscopy (TEM) and high‐resolution (HR)‐TEM confirm the formation of TiO₂/NaYF₄:Yb³⁺,Er³⁺ nano‐heterostructures. The up‐converted fluorescence spectrum of the photoanode containing the nano‐heterostructure confirms electron injection from NaYF₄:Yb³⁺,Er³⁺ to the condution band (CB) of TiO₂. When using a photoanode containing the nano‐heterostructure in a DSC, the overall efficiency (η) of the device is 17% higher than that of a device without the up‐conversion nanoparticles (UCNPs) and 13% higher than that of a device containing mixed TiO₂ and UCNPs. Nano‐heterostructures of TiO₂/NaYF₄:Yb³⁺,Tm³⁺ and TiO₂/NaYF₄:Yb³⁺,Ho³⁺ can also be prepared in situ on TiO₂ photoanodes. The overall efficiency of the device containing TiO₂/NaYF₄:Yb³⁺,Ho³⁺ nano‐heterostructures is 15% higher than the control device without UCNPs. When nano‐heterostructures of TiO₂/NaYF₄:Yb³⁺,Tm³⁺ are used, the open‐circuit voltage (V_oc) and the short‐circuit current density (J_sc) are all slightly decreased. The effect of the different UCNPs results from the different energy levels of Er³⁺, Tm³⁺, and Ho³⁺. These results demonstrate that utilizing the UCNPs with the apporpriate energy levels can lead to effective electron injection from the UCNPs to the CB of TiO₂, effectively improving the photocurrent and overall efficiency of DSCs while using NIR light.     

Dual‐Function Scattering Layer of Submicrometer‐Sized Mesoporous TiO2 Beads for High‐Efficiency Dye‐Sensitized Solar Cells

Submicrometer‐sized (830 ± 40 nm) mesoporous TiO₂ beads are used to form a scattering layer on top of a transparent, 6‐µm‐thick, nanocrystalline TiO₂ film. According to the Mie theory, the large beads scatter light in the region of 600–800 nm. In addition, the mesoporous structure offers a high surface area, 89.1 m² g^?1, which allows high dye loading. The dual functions of light scattering and electrode participation make the mesoporous TiO₂ beads superior candidates for the scattering layer in dye‐sensitized solar cells. A high efficiency of 8.84% was achieved with the mesoporous beads as a scattering layer, compared with an efficiency of 7.87% for the electrode with the scattering layer of 400‐nm TiO₂ of similar thickness.     

The Role of Insulating Oxides in Blocking the Charge Carrier Recombination in Dye‐Sensitized Solar Cells

Electron recombination is one of the major loss factors in dye‐sensitized solar cells (DSC), especially, with single electron outer sphere redox shuttle electrolyte. Insulating sub‐nanometer oxide tunneling layers deposited by atomic layer deposition (ALD) are known to block the electron recombination, thereby leading to an increase in the open‐circuit potential and the collection efficiency of the solar cell. A general perception in the DSC community is that any insulating oxide layer can block the recombination. However, in this work, it is unraveled that the insulating property of oxides alone is not sufficient. In addition, the properties such as the conduction band position and the oxidation state of the insulating oxide, the electronic structural modification induced to the underlying TiO₂ mesoporous film, modification of surface charges (isoelectric point) and charge of the electrolyte species have to be considered. A complete photovoltaic study is done by depositing different cycles (by ALD) of four different insulating oxides (Ga₂O₃, ZrO₂, Nb₂O₅, and Ta₂O₅) and their recombination characteristics, surface electronic properties, transport rate, and injection dynamics are investigated with a standard organic dye and Co²⁺/Co³⁺ redox mediator. A comparison is made with the conventional iodide/triiodide electrolyte.     

TiO2 Microspheres with Controllable Surface Area and Porosity for Enhanced Light Harvesting and Electrolyte Diffusion in Dye‐Sensitized Solar Cells

An optimized configuration of TiO₂ microspheres in photoanodes is of great importance to prepare highly efficient dye‐sensitized solar cells (DSSCs). In this work, TiO₂ microspheres with tunable diameter, pore size, and porosity are synthesized by subtly adjusting the synthesizing conditions, including ratios of deionized water, ammonia, and ethanol, respectively. TiO₂ microspheres are obtained with large pore sizes and a high porosity without sacrificing specific surface areas. In addition, the effect of their porosity and pore size on the performance of DSSCs is investigated. As confirmed by the dye‐loading ability and electrolyte diffusion resistance, the large mesopores and the high porosity of the TiO₂ microspheres can improve dye adsorption and facilitate electrolyte diffusion, giving rise to a high light‐harvesting and electron collection efficiency. Consequently, the highest photocurrent of 19.21 mA cm^?2 and a power conversion efficiency of 9.98% are obtained by using the TiO₂ microspheres with the highest porosity, compared with a 9.29% efficiency demonstrated by the lowest porosity (an improvement of 7.4%). By modifying the interconnection and the external pores of the microspheres photoanode, a high efficiency of 11.67% is achieved for a DSSC based on the most potent TiO₂ microspheres.