染料敏化TiO2/WO3薄膜电池的光电变色

The light-to-electricity conversion process of the TiO2 nanostructured electrode sensitized by a dye was investigated using the photoelectrochemical method in this paper. At the same time, the WO3 thin film was electrodeposited on conducting glass. The results showed that the dye-sensitized nanoporous TiO2 film has the properties of energy conversion, along with good electrochromic properties of electrodeposited MoO3 thin film. A self-powered smart window was achieved by combining a dye-sensitized nanoporous TiO2 film as the photovoltaic layer and an electrodeposited WO3 film as the electrochromic layer. This window changed from being almost transparent to blue spontaneously under illumination, and thus could modulate light transmittance.     

Preparation of a nanoporous CaCO3-coated TiO2 electrode and its application to a dye-sensitized solar cell

A nanoporous CaCO3 overlayer-coated TiO2 thick film was prepared by the topotactic thermal decomposition of Ca(OH)2, and its performance as an electrode of a dye-sensitized solar cell was investigated. As compared to bare TiO2, nanoporous CaCO3-coated TiO2 provided higher specific surface area and, subsequently, a larger amount of dye adsorption; this in turn increased short-circuit current (Jsc). Furthermore, the CaCO3 coating demonstrated increased impedance at the TiO2/dye/electrolyte interface and increased the lifetime of the photoelectrons, indicating the improved retardation of the back electron transfer, which increases Jsc, open-circuit voltage (Voc), and fill factor (ff). Thereby, the energy conversion efficiency (eta) of the solar cell improved from 7.8 to 9.7% (an improvement of 24.4%) as the nanoporous CaCO3 layer was coated onto TiO2 thick films.     

Microstructure design of nanoporous TiO2 photoelectrodes for dye-sensitized solar cell modules

The optimization of dye-sensitized solar cells, especially the design of nanoporous TiO2 film microstructure, is an urgent problem for high efficiency and future commercial applications. However, up to now, little attention has been focused on the design of nanoporous TiO2 microstructure for a high efficiency of dye-sensitized solar cell modules. The optimization and design of TiO2 photoelectrode microstructure are discussed in this paper. TiO2 photoelectrodes with three different layers, including layers of small pore size films, larger pore size films, and light-scattering particles on the conducting glass with the desirable thickness, were designed and investigated. Moreover, the photovoltaic properties showed that the different porosities, pore size distribution, and BET surface area of each layer have a dramatic influence on short-circuit current, open-circuit voltage, and fill factor of the modules. The optimization and design of TiO2 photoelectrode microstructure contribute a high efficiency of DSC modules. The photoelectric conversion efficiency around 6% with 15 x 20 cm2 modules under illumination of simulated AM1.5 sunlight (100 mW/cm2) and 40 x 60 cm2 panels with the same performance tested outdoor have been achieved by our group.     

电沉积法制备固态染料敏化太阳能电池

本文采用一步电化学沉积的方法在导电玻璃上先后沉积了ZnO/染料复合薄膜以及CuSCN薄层,实现仅以电沉积法制备结构为ZnO/染料/CuSCN的固态染料敏化太阳能电池,电池的光电转换效率达到0.1%.在电沉积CuSCN前,脱附电沉积制备的ZnO/染料复合薄膜中的染料以形成多孔ZnO薄膜,然后通过染料再吸附得到染料敏化ZnO纳晶多孔薄膜.在电沉积过程中,ZnO和CuSCN的晶体尺寸、晶体取向和膜层形貌都可以进行比较精准的控制.探讨了影响沉积薄膜形貌和光电转换效率的因素,如旋转圆盘电极的旋转速度、电沉积温度以及染料敏化剂的选择.本文报道的低温电沉积制备全固态太阳能电池的方法为制备柔性染料敏化太阳能电池提供了一种新的思路.     

Improving the performance of solid-state dye-sensitized solar cell using MgO-coated TiO2 nanoporous film

An ultrathin overlayer of MgO on TiO2 is shown to drastically improve the stability of solid-state dye-sensitized solar cell using CuI as a hole conductor in addition to solar energy conversion efficiency.     

Porous copper zinc tin sulfide thin film as photocathode for double junction photoelectrochemical solar cells

Porous copper zinc tin sulfide (CZTS) thin film was prepared via a solvothermal approach. Compared with conventional dye-sensitized solar cells (DSSCs), double junction photoelectrochemical cells using dye-sensitized n-type TiO(2) (DS-TiO(2)) as the photoanode and porous p-type CZTS film as the photocathode shows an increased short circuit current, external quantum efficiency and power conversion efficiency.     

Efficiency enhancement in dye-sensitized solar cells using hierarchical TiO2 submicron size spheres as a light scattering layer

Journal of Solid State Electrochemistry - The photoanode of a dye-sensitized solar cell (DSSC), usually made with a nanoporous TiO2 semiconductor layer sensitized with N719 dye, plays a crucial...     

Efficiency enhancement of solid‐state dye sensitized solar cell by in situ deposition of CuI

Solid‐state dye‐sensitized solar cells based on nanocrystalline TiO₂ thin film with the structures TiO₂/dye/CuI/Pt and TiO₂/dye/In situ CuI/CuI/Pt were developed in order to compare the use of In situ deposited CuI (In situ CuI). Porosity of the screen‐printed nanoporous TiO₂ thin film was enhanced by the addition of polystyrene balls. Evidence of decrease in interfacial resistance was observed by electrochemical impedance measurement for the device with In situ deposited CuI as compared to that without In situ deposited CuI as hole conductor. This was attributed to good interfacial contacts and better charge transfer between CuI and dye‐sensitized TiO₂ nanoparticles, which resulted in the enhancement of power conversion efficiency from 0.058 to 1.01%. Copyright © 2008 John Wiley & Sons, Ltd.     

电泳沉积法制备介孔TiO2/单壁碳纳米管薄膜

采用电泳沉积法, 在FTO/介孔TiO2薄膜上制备了介孔TiO2/单壁碳纳米管(SWCNTs)薄膜电极, 用Raman和SEM等手段对薄膜电极进行了表征. 结果表明, SWCNTs已沉积到介孔TiO2薄膜上. 分别用四羧基苯基卟啉(TCPP)和联吡啶钌化合物N719对其进行敏化, 并组装成太阳能电池. 研究结果表明, 与单纯的TiO2粒子膜相比, 介孔TiO2和SWCNTs的紧密结合可使得光生电子更容易传输, 光电转换效率显著提高.     

Correlation between dispersion properties of TiO2 colloidal sols and photoelectric characteristics of TiO2 films

TiO2 film for use as dye-sensitized solar cell was prepared using the TiO2 colloidal sols (unpeptized sol and peptized sol). The optical properties and photocurrent-voltage characteristics of the resultant films were investigated. The optical transmittance of TiO2 thin film prepared from the peptized colloidal sol was over 90%, while that of TiO2 film from the unpeptized sol was under 80%. The TiO2 photoelectrode prepared from the peptized colloidal sol showed low photoelectric conversion efficiency (eta), 1.30%, whereas the efficiency of photoelectrode from the unpeptized sol was 2.21%. The high optical transmittance and low conversion efficiency of TiO2 film from the peptized sol are discussed in terms of dense microstructure due to the drying nature of well-dispersed colloidal sol.     

Deposition of a thin film of TiOx from a titanium metal target as novel blocking layers at conducting glass/TiO2 interfaces in ionic liquid mesoscopic TiO2 dye-sensitized solar cells

In dye-sensitized TiO2 solar cells, charge recombination processes at interfaces between fluorine-doped tin oxide (FTO), TiO2, dye, and electrolyte play an important role in limiting the photon-to-electron conversion efficiency. From this point of view, a high work function material such as titanium deposited by sputtering on FTO has been investigated as an effective blocking layer for preventing electron leakage from FTO without influencing electron injection. X-ray photoelectron spectroscopy analysis indicates that different species of Ti (Ti4+, Ti3+, Ti2+, and a small amount of Ti0) exist on FTO. Electrochemical and photoelectrochemical measurements reveal that thin films of titanium species, expressed as TiOx, work as a compact blocking layer between FTO and TiO2 nanocrystaline film, improving Voc and the fill factor, finally giving a better conversion efficiency for dye-sensitized TiO2 solar cells with ionic liquid electrolytes.     

Triton X-100对染料敏化太阳电池性能影响的研究

采用无水相体系的胶体通过丝网印刷工艺制备TiO2薄膜电极,研究发现曲拉通(TritonX-100)可以明显改变TiO2电极显微结构,且对染料敏化太阳电池的性能影响显著.过少或过多的曲拉通都将导致开路电压、短路电流、填充因子以及效率的降低.由3gP25粉末配制的胶体中,曲拉通适宜的加入量约为0.8mL.     

TiO2 surface modification and characterization with nanosized PbS in dye-sensitized solar cells

The nanoporous TiO2 films utilized in dye-sensitized solar cells (DSSCs) possess a large surface-to-volume ratio, which facilitates the adsorption of sensitizing dye and the recombination due to the high density of surface traps. In this paper, nanosized PbS was fabricated on the TiO2 films. The components of the modified TiO2 film were studied by X-ray diffraction (XRD) and electron probe microanalysis (EPMA), while the structure of the film was characterized with BET physisorption and high-resolution scanning electron microscopy (HRSEM). The results showed that the PbS particles were 2-3 nm and discrete on the surface of TiO2. Diffusion photovoltage (PV) spectroscopy was employed to study the charge separation and diffusion processes inside modified and unmodified TiO2 films. The diffusion PV signals revealed that the traps on the surface of TiO2 were extremely reduced due to the presence of PbS. The results of transient photovoltage and back I-V characteristics showed that the back reaction, that is, the recombination due to the reaction between an electron on TiO2 and the hole-transporting media, was retarded significantly.     

Room-temperature preparation of nanocrystalline TiO2 films and the influence of surface properties on dye-sensitized solar energy conversion

An extremely easy method is presented for producing surfactant-free films of nanocrystalline TiO2 at room temperature with excellent mechanical stability when deposited on glass or plastic electrodes for dye-sensitized solar energy conversion. Prolonged magnetic stirring of commercial TiO2 nanoparticles (Degussa P25) in either ethanol or water results in highly homogeneous dispersions which are used to prepare TiO2 films with surface properties which depend on the solvent used for dispersing the particles, even after sintering. The optical and mechanical properties of films cast from ethanol and water dispersions are compared, and differences in the extent of surface defects and dye binding are observed. Optical absorption, photoluminescence, and resonance Raman spectra of TiO2 films sensitized with Ru(4,4'-dicarboxylic acid-2,2'-bipyridine)2(NCS)2 ("N3") reveal that the electronic coupling of the dye and semiconductor depends on the surface structure of the film which varies with film preparation. Current-voltage data for illuminated and dark dye-sensitized solar cells are obtained as a function of film preparation, and results are compared to spectroscopic data in order to interpret the microscopic basis for variations in solar cell performance, especially with regard to sintered versus unsintered TiO2 films. The results suggest that surface traps associated with oxygen vacancies play a critical role in determining the efficiency of dye-sensitized solar energy conversion through their influence on the binding and electronic coupling of the dye to the semiconductor.     

Highly efficient plastic substrate dye-sensitized solar cells using a compression method for preparation of TiO(2) photoelectrodes

The efficiency of a plastic-substrate dye-sensitized solar cell was much improved by a new method consisting of a press method without heat treatment, light confinement effect of TiO(2) film and water-based TiO(2) paste; this device shows the highest light-to-electrical energy conversion efficiency based on plastic-substrate dye-sensitized solar cells, 7.4% under 100 mW cm(-2) (1 sun) AM1.5 illumination.     

Linkage of N3 dye to N3 dye on nanocrystalline TiO2 through trans-1,2-bis(4-pyridyl)ethylene for enhancement of photocurrent of dye-sensitized solar cells

Linking of N3 dye to another TiO2-attached N3 dye rendered an enhanced short-circuit photocurrent and thereby higher efficiency for the dye-sensitized solar cell with the pertinent TiO2 film electrode.     

TiO2/ZnO薄膜电极中光生电子的传输及其在太阳电池中的应用

制备了TiO2纳米颗粒和ZnO纳米棒混合的多孔薄膜电极, 利用瞬态光电压技术研究了染料敏化TiO2/ZnO薄膜中光生载流子的传输特性. 实验结果表明, ZnO纳米棒增加了薄膜中自由电子扩散速率, 减小了复合几率, 改善了能量转换效率.     

TiO2纳米片/巢状分级结构纳米阵列薄膜的制备及其在染料敏化太阳能电池中的应用

采用水热合成法在氟掺杂二氧化锡(FTO)导电玻璃基底上得到TiO2纳米阵列薄膜,并进一步通过NaOH溶液水热处理制备了由巢状纳米阵列及纳米片覆盖层构成的TiO2纳米阵列分级结构一体化薄膜.采用场发射扫描电镜(FE-SEM),X射线衍射(XRD),紫外-可见(UV-Vis)漫反射光谱和吸收光谱技术对TiO2薄膜的结构和性质进行表征.FE-SEM结果表明:分级结构TiO2薄膜膜厚为1.5μm,薄膜由一层纳米片覆盖层(约0.2μm高)和一层巢状纳米阵列层(约1.3μm高)组成.XRD谱图表明TiO2薄膜为锐钛矿相.UV-Vis光谱显示分级结构TiO2薄膜具有较强的光捕获能力和染料吸附能力.TiO2纳米片/巢状分级结构纳米阵列薄膜作为光阳极,可有效地提高染料敏化太阳能电池的光电转换效率,其短路电流(Jsc)为7.79mA·cm-2,开路电压(Voc)为0.80V,填充因子(FF)为0.40,光电转换效率(η)为2.48%,其光电转换效率较TiO2纳米阵列薄膜提高了近10倍.     

十八硫醇自组装膜对TiO2光电氧化甲醇的敏化作用

纳米电极;甲醇光电氧化;十八硫醇自组装膜对TiO2光电氧化甲醇的敏化作用     

Nanoporous TiO2/polyion thin-film-coated long-period grating sensors for the direct measurement of low-molecular-weight analytes

We present novel nanoporous TiO(2)/polyion thin-film-coated long-period fiber grating (LPFG) sensors for the direct measurement of low-molecular-weight chemicals by monitoring the resonance wavelength shift. The hybrid overlay films are prepared by a simple layer-by-layer deposition approach, which is mainly based on the electrostatic interaction of TiO(2) nanoparticles and polyions. By the alternate immersion of LPFG into dispersions of TiO(2) nanoparticles and polyions, respectively, the so-formed TiO(2)/polyion thin film exhibits a unique nanoporous internal structure and has a relative higher refractive index than LPFG cladding. In particular, the porosity of the thin film reduces the diffusion coefficient and enhances the permeability retention of low-molecular-weight analytes within the porous film. The increases in the refractive index of the LPFG overlay results in a distinguished modulation of the resonance wavelength. Therefore, the detection sensitivity of LPFG sensors has been greatly improved, according to theoretical simulation. After the structure of the TiO(2)/polyion thin film was optimized, glucose solutions as an example with a low concentration of 10(-7) M was easily detected and monitored at room temperature.