纳米TiO2多孔薄膜电极平带电势的研究

采用光谱电化学方法研究了纳米TiO₂多孔薄膜电极的平带电势,获得了薄膜厚度以及TiCl₄处理对纳米TiO₂薄膜电极平带电势的影响情况,并研究了平带电势对染料敏化太阳电池光伏性能的影响.结果表明,可以通过检测纳米TiO₂电极平带电势的变化趋势来反映电池中TiO₂电极平带电势的变化趋势.随着TiO₂电极膜厚的增加,其平带电势将向正方向移动,导致对应电池的开路电压随之减小.另外,经 关键词： 平带电势 2')" href="#">纳米TiO₂ 染料敏化 太阳电池     

锐钛矿相TiO2纳米管的制备及其染料敏化太阳电池

以商用金红石相TiO₂粉末为原料,通过在碱性溶液中150℃水热48h的方法合成TiO₂纳米管.采用SEM,TEM,XRD分析手段对TiO₂纳米管的形貌和结构演变进行了表征.制成的TiO₂纳米管与TritonX-100,乙酰丙酮混合后,通过丝网印刷的方法涂敷到ITO导电玻璃衬底上,并且在450℃下烧结30min后得到可应用于染料敏化太阳电池的多孔光阳极.将此光阳极浸泡于N719染料敏化后,与镀铂对电极组装电池,两者之间灌 关键词： 2纳米管')" href="#">TiO₂纳米管 染料敏化太阳电池 水热法     

TiCl4处理多孔薄膜对染料敏化太阳电池中电子传输特性影响研究

借助于强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)技术,研究了纳米TiO₂多孔薄膜在TiCl₄溶液处理后组装成的染料敏化太阳电池(DSC)中电子传输和背反应动力学特性. 研究表明:纳米TiO₂多孔薄膜经TiCl₄溶液处理后,电池中暗电流减小,电子寿命τ_n明显延长,电子传输时间τ_d缩短,电子有效扩散系数D_n增大,电子扩散长度L_n值升高,入射单色光子/电子转化效率η_IPCE增加,光生电荷量Q_oc显著增加. 文章从微观层面上研究了TiCl₄溶液处理纳米TiO₂多孔薄膜对DSC内部电子的产生、传输和复合过程的影响,从而很好地解释了电池光伏性能随TiCl₄溶液处理的变化关系. 关键词： 4')" href="#">TiCl₄ 电子传输 染料敏化 太阳电池     

电极表面改性对染料敏化太阳电池性能影响的机理研究

采用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)技术,从染料敏化太阳电池(DSC)电子传输和复合角度对比了不同光强下导电玻璃表面阻挡层及TiO₂薄膜优化使电池性能改善的内在原因.阻挡层的引入和TiO₂薄膜的优化均通过电沉积法实现.结果表明,对多孔薄膜电极的不同改性均提高了电池的短路电流J_sc和效率η,但对电子传输和复合过程的作用机理有所不同:前者延长了电子寿命τ _n,但电子传输时间τ _d变化不明显;而后者则主要是延长τ _n的同时也缩短了τ _d. 关键词： 染料敏化 太阳电池 调制光电流谱/调制光电压谱 电子输运     

染料敏化纳米ZnO薄膜太阳电池机理初探

讨论利用ZnO代替TiO2作为光阳极制作染料敏化薄膜太阳电池的可行性.使用LSV法，IR光谱和UV-vis光谱探讨了电池的工作机理和性能，并与染料敏化纳米TiO2薄膜太阳电池作了比较.结果发现ZnO薄膜表面与染料的吸附键合力太弱是导致ZnO太阳电池效率低下的主要原因. 关键词： 纳米ZnO 太阳电池 染料敏化 量子效率     

TiO2颗粒尺寸对染料敏化太阳电池内电子输运特性影响研究

采用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)研究了染料敏化太阳电池(DSC)内部电子传输和背反应动力学特性.在纳米TiO₂薄膜厚度相同的情况下,借助于IMPS/IMVS测量了由3种不同TiO₂颗粒尺寸大小薄膜制备出DSC的电荷传输特征参数值.IMPS/IMVS理论模型拟合实验测量数据的结果表明：在不同入射光强下,随着颗粒尺寸的增大,电子扩散系数(D_n)增大,而电子寿命(τ_n 关键词： 染料敏化 太阳电池 IMPS/IMVS 电子传输     

纳米TiO2叶片状阵列电极的制备及其在染料敏化太阳电池中电子的输运性能

在低温条件下采用定向刻蚀技术, 对金属Ti片表面用H₂O₂溶液进行刻蚀氧化, 制备了垂直生长的纳米TiO₂叶片状阵列薄膜电极. 通过X射线衍射分析表明, 纳米TiO₂叶片状阵列薄膜经500 ℃下烧结1 h后, 从无定型转变为锐钛矿相. 场发射扫描电子显微镜观察表明: 在80 ℃下的H₂O₂溶液刻蚀氧化, 经1 d制备得到的是Ti片表面垂直生长的叶片状阵列, 其形貌均匀且完整地 关键词： 2')" href="#">纳米TiO₂ 叶片状阵列电极 染料敏化太阳电池 电子传输     

纳米TiO2颗粒/亚微米球多层结构薄膜内电荷传输性能研究

本文主要利用TiO₂亚微米球较强的光散射特性设计了纳米TiO₂颗粒/亚微米球多层结构光阳极, 并借助强度调制光电流谱(intensity-modulated photocurrent spectroscopy)、电化学阻抗谱(electrochemical impedance spectroscopy)和入射单色光光电转化效率(incident photon-to-current conversion efficiency), 研究亚微米球的引入对多层结构薄膜内缺陷态、电子传输时间、电子收集效率和界面电荷转移性能的影响. 强度调制光电流谱反映出亚微米球表面缺陷态少, 但其颗粒间接触不紧密, 导致在接触部位形成了势垒, 阻碍了电子的传输, 导致电子传输时间增长. 电化学阻抗谱结果表明不同多层结构电池界面复合无明显差别, 同时底层采用纳米TiO₂ 透明薄膜结构的电池, 其光利用率要明显高于底层采用亚微米球薄膜结构的电池, TiO₂费米能级电子填充水平也相对增大, 使得电池的光电转换效率得到提升. 多层结构复合薄膜电荷传输和光伏特性的研究, 为高效染料敏化太阳电池光阳极设计提供了实验基础.     

丝网印刷制备染料敏化太阳能电池

染料敏化太阳能电池（DSSC）是太阳能电池研究的热点领域之一,使用丝网印刷技术制备以纳米晶多孔TiO₂薄膜为光阳极的DSSC具有低成本、简单的制备工艺和高的光电转换效率（PCE）的特点,这类太阳能电池受到人们广泛关注。为了提高这类太阳能电池的光电转换效率,通过采用不同网目相同印刷胶体制备了太阳能电池的光阳极优化印刷工艺十分重要,采用不同网目的方法研究印刷工艺对太阳能电池光伏性能的影响是十分有效的。用溶胶-凝胶法制备了TiO₂胶体,通过扫描电镜看出TiO₂薄膜具有多孔结构,其高比表面积有利于薄膜对染料分子的吸附,也有利于提高电池对太阳光的吸收率。经过高温烧结后丝网印刷的TiO₂薄膜展现了明显的锐钛矿结构较窄衍射峰,意味着TiO₂颗粒已经完全晶化且粒径增加。制备目数从100增到300导致网孔直径减少而薄膜变得更加致密,使得TiO₂薄膜的XRD衍射峰逐渐增强,而从300目增到400目时由于网孔过小导致TiO₂胶体通过网孔数量变小使得衍射峰强度下降。用不同网目印刷了单层TiO₂光阳极研究DSSCs光伏性能的变化情况,发现制备目数是200目和300目印刷太阳能电池的性能较好,而400网目印刷太阳能电池的性能最差,这与XRD观察的结果一致。再分别采用网目为100目、200目、300目和400目的印网将胶体印刷成了多层TiO₂薄膜,以此为基础组装DSSC。实验结果表明：通过不同组合网目的丝网印刷制备TiO₂薄膜,组装后的染料敏化太阳能电池的光电转换效率得到了显著提升,其中以300目+200目+100目三层叠印时得到的优化光阳极的最高电池效率达到6.9%。以丝网印刷的方法制备电极不需要进行任何化学处理,在较高网目制备底层的情况下印刷的薄膜均匀牢固,且电池制备的步骤简单、重复性好,能量转换效率较高。     

染料敏化太阳电池中TiO2颗粒界面接触对电子输运影响的研究

采用溶胶-凝胶法制备TiO₂浆料,通过丝网印刷技术印刷和不同温度曲线烧结TiO₂薄膜,并应用于染料敏化太阳电池(DSC).高分辨透射电子显微镜发现,低温下多孔薄膜中TiO₂颗粒之间呈现点接触,510 ℃烧结后TiO₂颗粒间由点接触变为面接触,近邻颗粒数增多,接触面积增大.同时采用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)技术,研究了不同颗粒接触方式和接触面积对电子传输与复合的影响.结果表明:在420- 510 ℃之间,随着烧结温度提高,颗粒接触面积增大,电子传输时间(τ _d)缩短,电子有效扩散长度(L _n)增大,暗电流减小;当烧结温度达到550 ℃时,薄膜比表面积减小,多孔结构坍塌,表面态密度增大,电子传输时间(τ _d)增大.电池光伏特性研究表明:在480-510 ℃范围内烧结得到的TiO₂薄膜,电池短路电流密度(J_sc)最佳,电池效率(η)最好. 关键词： 界面接触 电子输运 暗电流 染料敏化太阳电池     

Growth of nanocrystalline TiO2 films by pulsed-laser-induced liquid-deposition method and preliminary applications for dye-sensitized solar cells

A novel technique, the pulsed-laser-induced liquid-deposition (PLLD) method, has been employed to grow nanocrystalline TiO₂ films on fluorine-doped tin-oxide-coated (FTO) glass substrates at room temperature. The PLLD method was implemented by directing a pulsed laser into a liquid precursor and depositing the photosynthesized nanocrystalline TiO₂ on an FTO glass substrate immersed in the liquid precursor. The as-grown nanocrystalline TiO₂ films were found to have a rutile crystal structure and consist of a number of flower-like TiO₂ crystal units arrayed together on the FTO glass substrate. Each of the flower-like TiO₂ crystal units was composed of many nanostructured TiO₂ whiskers, and their building blocks were found to be bundles of TiO₂ nanorods with diameter of about 5 nm. The growth of these TiO₂ nanorods is highly anisotropic, with the preferential growth direction along [001]. As-grown nanocrystalline TiO₂ films were annealed at 450°C in air for 30 min for the applications of dye-sensitized solar cells, and the nanostructured characteristics with good porosity were preserved after annealing. A preliminary dye-sensitized solar cell was built based on the annealed nanocrystalline TiO₂ film. The results suggest that the PLLD method is a promising technique for growing nanocrystalline TiO₂ films for photovoltaic applications.     

纳米TiO2多孔膜的微结构对染料敏化纳米薄膜太阳电池性能的影响

采用溶胶-凝胶方法，在不同的实验条件下获得平均粒径从15到25nm左右的纳米TiO２2颗粒.利用这些颗粒制备出的纳米多孔薄膜，应用于染料敏化纳米薄膜太阳电池. 通过x射线 衍射仪分析，得到TiO２₂颗粒的晶相以及晶粒度大小，用透射电子显微镜观察 了纳米TiO２₂颗粒的形貌和尺寸.应用于太阳电池的纳米TiO２₂多 孔膜，经基于布朗诺尔-埃米特-泰 勒（BET）的多层吸附理论的比表面积测试和孔径分布测试，获得了多孔膜的微 关键词： 溶胶-凝胶法 2')" href="#">纳米TiO２₂ 染料敏化 太阳电池     

Influence of Yb-Doped Nanoporous TiO2 Films on Photovoltaic Performance of Dye-Sensitized Solar Cells

Yb-doped TiO2 pastes with different Yb/TiO2 weight ratios are prepared in the sol-gel process to obtain dyesensitized solar cells （DSCs）. The nanocrystalline size of Yb-TiO2 becomes smaller and the lattice parameters change. Lattice distortion is observed and dark current is detected. It is found that a part of Yb existing as insulating oxide Yb2O3 state acts as barrier layers at the electrode-electrolyte interface to suppress charge recombination. A Yb-doped TiO2 electrode applied in DSCs leads to a higher open-circuit voltage and a higher fill factor. How the Yb-doped TiO2 films affect the photovoltaic response of DSCs is discussed.     

The control of the diameter of the nanorods prepared by dc reactive magnetron sputtering and the applications for DSSC

The TiO₂ nanorod arrays, with about 1.8 μm lengths, have been deposited on ITO substrates by dc reactive magnetron sputtering at different target-substrate distances. The average diameter of these nanorods can be modified from about 45 to 85 nm by adjusting the target-substrate distance from 90 to 50 mm. These nanorods are highly ordered and perpendicular to the substrate. Both XRD and Raman measurements show that the nanorods prepared at different target-substrate distances have only an anatase TiO₂ phase. The nanorods prepared at the target-substrate distance less than 80 mm have a preferred orientation along the (2 2 0) direction. However, this preferred orientation disappears as the target-substrate distance is more than 80 mm. These TiO₂ nanorods have been used as the electrodes for dye-sensitized solar cells (DSSCs). The highest conversion efficiency, about 4.78%, has been achieved for TiO₂ nanorods prepared at 80 mm target-substrate distance.     

Laser-sintered mesoporous TiO2 electrodes for dye-sensitized solar cells

Low-temperature laser sintering has been successfully demonstrated to improve the overall conversion efficiency of dye-sensitized solar cells. Mesoporous TiO₂ electrodes were prepared from a colloidal solution of TiO₂ nanopowders by a laser direct-write technique and then sintered by a quasi-continuous-wave UV laser (λ=355 nm) for the fabrication of dye-sensitized solar cells. The overall conversion efficiency of the cells based on the laser-sintered TiO₂ electrodes was double that of the devices with non-laser-treated TiO₂ electrodes. This enhancement is attributed to both the removal of organic additives and the improved inter-nanoparticle electrical contacts induced by the laser-sintering process, which led to an increase in porosity and dye-absorption sites in the TiO₂ electrodes. PACS 61.80.Ba; 61.46.+w; 73.22.-f; 84.60.Jt     

Study on the properties and charge generation in dye-sensitized n-TiO2|dye|p-CuI solid state photovoltaic solar cells

Transparent semiconducting copper iodide (CuI) films were prepared by XeCl Excimer laser and their characteristics are investigated. These films exhibited optical transmittance over 80% in the wavelength range from 400 to 900 nm and minimum resistivity of about 2 kΩ cm⁻¹. The optical absorption of the these films shows a remarkable blue shift compared to that of polycrystalline of CuI, which can be explained from the viewpoint formation of ultra fine of CuI grains. The titanium dioxide (TiO₂) films have been prepared by sol-gel method. The properties of pulsed laser deposited CuI and TiO₂ films in power output of n-TiO₂|dye|p-CuI cells is studied. An efficient charge generation is observed through the illumination of TiO₂ layer of the fabricated n-TiO₂|dye|p-CuI solid state photovoltaic solar cells. From the current-voltage characteristics, the fill factor and power conversion efficiency were about of 45 and 3%, respectively. The maximum photo-current of about 12.5 mA/cm² and photo-voltage of 475 mV under AM 1.5 conditions were obtained for the n-TiO₂|dye|p-CuI solid states photovoltaic solar cells with good reproducibility. Adsorbed dye molecules to the TiO₂ surface act as a relay, especially under illumination through TiO₂ layer in the wave range region of 300-400 nm.     

XPS characterization of sensitized n-TiO2 thin films for dye-sensitized solar cell applications

TiO₂ thin films, employed in dye-sensitized solar cells, were prepared by the sol-gel method or directly by Degussa P25 oxide and their surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The effect of adsorption of the cis-[Ru(dcbH₂)₂(NCS)₂] dye, N3, on the surface of films was investigated. From XPS spectra taken before and after argon-ion sputtering procedure, the surface composition of inner and outer layers of sensitized films was obtained and a preferential etching of Ru peak in relation to the Ti and N ones was identified. The photoelectrochemical parameters were also evaluated and rationalized in terms of the morphological characteristics of the films.     

金属氧化物修饰对介孔纳米TiO2电极的染料敏化太阳能电池电化学性能的影响

将介孔TiO₂纳米粒子(m-TiO₂)多孔膜电极浸入相应的金属硝酸盐的500 oC热处理修饰金属氧化物(如Mg、ZnO、Al₂O₃或NiO).结果表明,金属氧化物修饰均可形成能垒对m-TiO₂膜电极的界面电荷传输过程产生影响,但外加偏压下其膜内电子传输和界面电荷复合均明显依赖于修饰氧化物的种类及其存在形态. 金属氧化物修饰的膜电极在电子传输和界面复合方面的变化与DSSCs的电流-电压特性曲线的变化规律具有明显的相关性,可不同程度地提高电池的光电压,而MgO、ZnO和NiO修饰的电池效率分别提高了23%、13%和6%. 上述结果表明调控电池的本征参数可以改善TiO₂-基DSSCs的性能.     

Effects of 1064 nm laser on the structural and optical properties of nanostructured TiO2 thin film

TiO₂ thin film has been widely used as photoelectrode in dye-sensitized solar cells. It can also be used in quantum dot synthesized solar cells. Study of its effects in different spectrum of light is important for its use in solar cells. We have reported effects of 1064 nm laser on the surface morphology, structural and optical properties of nanostructured TiO₂ thin film deposited on glass substrates using sol-gel spin coating technique. Q-Switched Nd:YAG pulsed laser at various power densities is used in this study. Surface morphology of the film is investigated using X-ray diffraction (XRD) and atomic force microscopy technique. The XRD pattern of as deposited TiO₂ thin film is amorphous and after laser exposure it became TiO₂ anatase structure. Atomic force microscopy of the crystalline TiO₂ thin film shows that the grain size increases by increasing laser power density. The calculations of the band gap are carried out from UV/Visible spectroscopy measurements with JASCO spectrometer. For laser power density of 25 MW/cm² there is an increase in the transmission and it decreases at the value of 38 MW/cm² and band gap decreases with increasing laser power density. Photoluminescence spectra of the crystalline TiO₂ thin film indicate two broad peaks in the range of 415 and 463 nm, one for band gap peak (415 nm) and other for oxygen defect during film deposition process.     

TiO2 Nanoparticles Produced by Electric-Discharge-Nanofluid-Process as Photoelectrode of DSSC

利用自制TiO₂纳米粒子研究敏化染敏太阳能电池. 使用自制的旋转涂布加热平台装置将产出的TiO₂粒子均匀的涂布在ITO导电玻璃上形成薄膜,浸泡于N-719 染料中12小时以上作为DSSCs的光电极 元件,最后完成染料敏化太阳能电池的系统组装并进行光电转换效率测量. 实验结果表明,放电过程产出的TiO₂纳米粒子具有锐钛矿晶相,粒径尺寸可控制在20～70 nm,粒子表面电位约为-30 mV,是稳定的纳米悬浮夜. 添加0.5 mL 的Triton X-100在导电玻璃表面上,利用的旋转涂布加热到22 oC可以制得厚度均匀缜密的薄膜结构,不但粒子不受到热处理效应与介面活性剂的影响而发生晶相改变,并且薄膜也有良好的染料吸附效果. 较厚二氧化钛薄膜的光电极会提升敏化染敏太阳能电池的效率. 实验结果得知,以15 μm的二氧化钛薄膜组装DSSCs测得最高效率2.15%,但是当薄膜厚度超过15 μm 则会导致开路电压与充填因子逐渐下降,光电转换效率变差.