N,N′-对羧苄基吲哚三菁敏化纳米TiO2电极的研究

应用光电化学方法研究了N, N′-对羧苄基吲哚三菁（Cy5）染料敏化TiO2纳米晶电极的光电化学行为,优化了敏化的条件.结合Cy5的循环伏安曲线和光吸收阈值,初步确定Cy5电子基态和激发态能级位置.结果表明,Cy5电子激发态能级位置能与TiO2纳米粒子导带边位置相匹配,因而使用该染料敏化可以显著提高TiO2纳米晶的光电流,使TiO2纳米晶电极吸收波长由紫外光区红移至可见光区和近红外区,光电转换效率得到明显改善,在膜厚为6.5μm、敏化时间为6 h的条件下IPCE值（incident photo-to-electricity conversion efficiency）最高可达46.4％,总的光电转换效率η为1.70％.     

Formation of efficient dye-sensitized solar cells by introducing an interfacial layer of long-range ordered mesoporous TiO2 thin film

Long-range ordered cubic mesoporous TiO 2 films with 300 nm thickness were fabricated on fluorine-doped tin oxide (FTO) substrate by evaporation-induced self-assembly (EISA) process using F127 as a structure-directing agent. The prepared mesoporous TiO 2 film (Meso-TiO 2) was applied as an interfacial layer between the nanocrystalline TiO 2 film (NC-TiO 2) and the FTO electrode in the dye-sensitized solar cell (DSSC). The introduction of Meso-TiO 2 increased J sc from 12.3 to 14.5 mA/cm (2), and V oc by 55 mV, whereas there was no appreciable change in the fill factor (FF). As a result, the photovoltaic conversion efficiency ( eta) was improved by 30.0% from 5.77% to 7.48%. Notably, introduction of Meso-TiO 2 increased the transmittance of visible light through the FTO glass by 23% as a result of its excellent antireflective role. Thus the increased transmittance was a key factor in enhancing the photovoltaic conversion efficiency. In addition, the presence of interfacial Meso-TiO 2 provided excellent adhesion between the FTO and main TiO 2 layer, and suppressed the back-transport reaction by blocking direct contact between the electrolyte and FTO electrode.     

聚3-甲基噻吩修饰硫化物量子点连接纳米结构TiO2膜的光电化学研究

采用原位化学法在纳米结构TiO₂膜上制备了量子点CdS, PbS (Q-CdS, Q-PbS), 并用电化学方法在TiO₂/Q-CdS, TiO₂/Q-PbS表面聚合3-甲基噻吩[poly(3-Methylthiophene, PMeT)]. 用光电化学方法研究了PMeT修饰Q-CdS, Q-PbS连接TiO₂纳米结构膜, 实验结果表明, PMeT和Q-CdS, Q-PbS单独修饰纳米结构TiO₂电极和PMeT修饰Q-CdS, Q-PbS连接纳米结构TiO₂电极的光电流产生的起始波长都向长波方向移动; 一定条件下在可见光区光电转换效率均较纳米结构TiO₂的光电转换效率有明显的提高; 聚3-甲基噻吩(PMeT)与Q-CdS, Q-PbS连接的纳米结构TiO₂之间存在p-n异质结. 在一定条件下p-n异质结的存在有利于光生电子/空穴的分离, 在本文实验条件下PMeT修饰Q-CdS, Q-PbS连接纳米结构TiO₂电极最高的单色光的光电转换效率分别为11%和7%.     

Influence of a TiCl4 post-treatment on nanocrystalline TiO2 films in dye-sensitized solar cells

In this study, the influence of the TiCl(4) post-treatment on nanocrystalline TiO(2) films as electrodes in dye-sensitized solar cells is investigated and compared to nontreated films. As a result of this post-treatment cell efficiencies are improved, due to higher photocurrents. On a microscopic scale TiO(2) particle growth on the order of 1 nm is observed. Despite a corresponding decrease of BET surface area, more dye is adsorbed onto the oxide surface. Although it seems trivial to match this finding with the improved photocurrent, this performance improvement cannot be attributed to higher dye adsorption only. This follows from comparison between incident photon to current conversion efficiency (IPCE) and light absorption characteristics. Since the charge transport properties of the TiO(2) films are already more than sufficient without treatment, the increase in short circuit current density J(SC) cannot be related to improvements in charge transport either. Transient photocurrent measurements indicate a shift in the conduction band edge of the TiO(2) upon TiCl(4) treatment. It is concluded that the main contribution to enhanced current originates from this shift in conduction band edge, resulting in improved charge injection into the TiO(2).     

Synthesis and photophysical properties of ruthenium-based dendrimers and their use in dye sensitized solar cells

First- and second-generation dendrimers (Ru3 and Ru6) have been synthesized, and their photophysical properties were investigated in solution and when adsorbed on the nanocrystalline TiO2 surface. The performance of Ru3 and Ru6 as charge transfer photosensitizers in nanocrytalline TiO2 based solar cells was also investigated. The best photovoltaic performance was obtained by the Ru3 based solar cell yielding a short circuit current of J sc = 5.52 mA.cm (-2) and an open circuit voltage of V oc = 626 mV, corresponding to an overall conversion efficiency of eta = 1.80% that is approximately double the conversion efficiency of the reference compound Ru1 (eta = 0.91%) and of the second generation dendrimer Ru6 (eta = 0.95%). The particular efficiency of the first generation dendrimer, Ru3, is attributed to the better light-harvesting properties of the doped nanocrystalline TiO2 film when compared to Ru1, whereas the poor performance of the second generation dendrimer, Ru6, is attributed to the uneven adsorption of all of the ruthenium moieties to the nanocrystalline TiO2 surface at the same time.     

3d过渡金属掺杂TiO2纳米晶膜电极的光电化学研究

应用原子力显微镜和X射线粉末法对3d过渡金属离子Cr(Ⅲ),Fe(Ⅲ),Mn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ)和Zn(Ⅱ)掺杂TiO₂纳米晶粒(简写为m^3d-TiO₂)作了表征,并用光电化学方法研究了m^3d-TiO₂纳米结构多孔膜电极.实验结果表明,m^3d-TiO₂纳米粒子的颗粒较均匀,粒径约为15nm,其晶型为锐钛矿和板钛矿的混晶.在所研究的m^3d-TiO₂中,只有Zn²⁺-TiO₂电极的光电流大于未掺杂的TiO₂纳米结构多孔膜电极.3d金属离子的掺杂引起各电极的光电流信号在一定波长范围内出现p-n转型现象.     

Squarylium Cyanine Dyes for Photoelectric Conversion

Asanimportantclassoffunctionalmaterials,squaryliumcyaninedyespossessmanyexcellentpropertiessuchasstablestructures,outstandingphotoconductivityaswellassmallthermalconductivity,andexhibitintenseandsharpabsorptionbandsinthevisibleandnearinfraredregionwithhighlightharvestingcapacity,whichopenupextensiveapplicationsinthevariousfieldsl-3.Inthispaper,twosymmetricalsquaryliumindocyanineswiththeintroductionofhydroxyethylandsulfopropylgroupsontheheterocyclicnitrogenweresynthesizedandcharacterizedbyUV,I…     

Artificial photosynthesis by using chloroplasts from spinach adsorbed on a nanocrystalline TiO2 electrode for photovoltaic conversion

Photovoltaic conversion has been achieved by use of chloroplasts (photosynthetic organs) from spinach adsorbed on a nanocrystalline TiO₂ film on an indium tin oxide (ITO) glass electrode (chloroplast/TiO₂ electrode). The shape of the absorption spectrum of the chloroplast/TiO₂ electrode is almost the same that of a dispersion of the chloroplasts. Absorption maxima of the chloroplast/TiO₂ electrode observed at 430, 475, and 670 nm were attributed to carotenoid and chlorophyll molecules, suggesting that chloroplasts have been adsorbed by the nanocrystalline TiO₂ film on the ITO electrode. The photocurrent responses of chloroplast/TiO₂ electrodes were measured by using a solution of 0.1 M tetrabutylammonium hexafluorophosphate in acetonitrile as redox electrolyte in the presence or absence of water and 100 mW cm^?2 irradiation. The photocurrent of the chloroplast/TiO₂ electrode was increased by adding water to the redox electrolyte. The photocurrent responses of chloroplast/TiO₂ electrodes irradiated with monochromatic light (680 nm, the absorption band of photosystem II complexed with evolved oxygen) were measured by use of a solution of 0.1 M tetrabutylammonium hexafluorophosphate in acetonitrile as redox electrolyte in the presence or absence of water. A chloroplast/TiO₂ electrode photocurrent was observed only when the redox electrolyte containing water was used, indicating that the oxygen evolved from water by photosystem II in chloroplasts adsorbed by a nanocrystalline TiO₂ film on an ITO electrode irradiated at 680 nm is reduced to water by the catalytic activity of the platinum electrode. The maximum incident photon-to-current conversion efficiency (IPCE) was 0.8 % on irradiation at 670 nm.     

Engineering of a novel ruthenium sensitizer and its application in dye-sensitized solar cells for conversion of sunlight into electricity

A novel ligand 4,4'-bis(carboxyvinyl)-2,2'-bipyridine (L) and its ruthenium(II) complex [Ru(II)L(2)(NCS)(2)] (K8) were synthesized and characterized by analytical, spectroscopic, and electrochemical techniques. The performance of the K8 complex as a charge transfer photosensitizer in nanocrystalline TiO(2) based solar cells was studied. When the K8 complex anchored onto a nanocrystalline TiO(2) film, we achieved very efficient sensitization yielding 77 +/-5% incident photon-to-current efficiencies (IPCE) in the visible region using an electrolyte consisting of 0.6 M methyl-N-butyl imidiazolium iodide, 0.05 M iodine, 0.05 M LiI, and 0.5 M 4-tert-butylpyridine in a 50/50 (v/v) mixture of valeronitrile and acetonitrile. Under standard AM 1.5 sunlight, the complex K8 gave a short circuit photocurrent density of 18 +/- 0.5 mA/cm(2), and the open circuit voltage was 640 +/- 50 mV with fill factor of 0.75 +/- 0.05, corresponding to an overall conversion efficiency of 8.64 +/- 0.5%.     

Starburst triarylamine based dyes for efficient dye-sensitized solar cells

We report here on the synthesis and photophysical/electrochemical properties of a series of novel starburst triarylamine-based organic dyes (S1, S2, S3, and S4) as well as their application in dye-sensitized nanocrystalline TiO2 solar cells (DSSCs). For the four designed dyes, the starburst triarylamine group and the cyanoacetic acid take the role of electron donor and electron acceptor, respectively. It was found that the introduction of starburst triarylamine group to form the D-D-pi-A configuration brought about superior performance over the simple D-pi-A configuration, in terms of bathochromically extended absorption spectra, enhanced molar extinction coefficients and better thermo-stability. Moreover, the HOMO and LUMO energy levels tuning can be conveniently accomplished by alternating the donor moiety, which was confirmed by electrochemical measurements and theoretical calculations. The DSSCs based on the dye S4 showed the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 85%, a short-circuit photocurrent density (J(sc)) of 13.8 mA cm(-2), an open-circuit photovoltage (V(oc)) of 0.63 V, and a fill factor (ff) of 0.69, corresponding to an overall conversion efficiency of 6.02% under 100 mW cm(-2) irradiation. This work suggests that the dyes based on starburst triphenylamine donor are promising candidates for improvement of the performance of the DSSCs.     

两种菁类染料复合敏化TiO2纳米晶电极的光电化学研究

应用光电化学方法研究了两种菁类染料Cy3和Cy5复合敏化TiO2纳米晶电极的光电化学行为. 结合两种染料的紫外-可见光谱和循环伏安曲线, 确定了Cy3和Cy5的电子基态和激发态能级位置. 结果表明两种染料的激发态能级位置能与TiO2纳米粒子导带边位置相匹配, 复合敏化可以显著提高TiO2纳米晶的光电流, 使TiO2纳米晶电极吸收波长由紫外光区红移至可见光区和近红外区. 复合敏化降低了染料Cy3在电极吸附时的聚集程度, 使其单色光的转换效率(IPCE)提高了169%, 复合敏化电极总的光电转换效率η为2.09%, 分别是Cy3和Cy5单独敏化时光电转换效率的2.069和1.229倍.     

聚3-甲基噻吩修饰量子点硫化铅连接TiO2纳米结构膜的光电化学研究

采用原位化学法在纳米结构TiO2电极上制备了量子点PbS(Q-PbS), 并用电化学方法在TiO2/Q-PbS表面聚合3-甲基噻吩[poly(3-Methylthiophene), PMeT]. 研究结果表明, PMeT和Q-PbS单独修饰纳米结构TiO2电极和PMeT修饰Q-PbS连接纳米结构TiO2电极的光电流产生的起始波长都向长波方向移动; 在可见光区光电转换效率均比纳米结构TiO2的光电转换效率提高显著; PMeT与Q-PbS修饰的纳米结构TiO2之间存在p-n异质结. 在一定条件下p-n异质结的存在有利于光生电子/空穴的分离, 提高了光电转换效率.     

纳米结构TiO2/聚3-己基噻吩多孔膜电极光电性能研究

用光电流作用谱、光电流-电势图等光电化学方法研究了ITO/聚3-己基噻吩(ITO/ P3HT)膜和纳米结构TiO2/聚3-己基噻吩(TiO2/P3HT)复合膜的光电转换性质. 结果表明, P3HT膜的禁带宽度为1.89 eV, 价带位置为－5.4 eV. 在ITO/TiO2/ P3HT复合膜电极中存在p-n异质结, 在一定条件下异质结的存在有利于光生电子-空穴对的分离. P3HT修饰ITO/TiO2电极可使光电流发生明显的红移, 从而提高了宽禁带半导体的光电转换效率.     

Enhanced water photolysis with Pt metal nanoparticles on single crystal TiO2 surfaces

Two novel deposition methods were used to synthesize Pt-TiO(2) composite photoelectrodes: a tilt-target room temperature sputtering method and aerosol-chemical vapor deposition (ACVD). Pt nanoparticles (NPs) were sequentially deposited by the tilt-target room temperature sputtering method onto the as-synthesized nanostructured columnar TiO(2) films by ACVD. By varying the sputtering time of Pt deposition, the size of deposited Pt NPs on the TiO(2) film could be precisely controlled. The as-synthesized composite photoelectrodes with different sizes of Pt NPs were characterized by various methods, such as SEM, EDS, TEM, XRD, and UV-vis. The photocurrent measurements revealed that the modification of the TiO(2) surface with Pt NPs improved the photoelectrochemical properties of electrodes. Performance of the Pt-TiO(2) composite photoelectrodes with sparsely deposited 1.15 nm Pt NPs was compared to the pristine TiO(2) photoelectrode with higher saturated photocurrents (7.92 mA/cm(2) to 9.49 mA/cm(2)), enhanced photoconversion efficiency (16.2% to 21.2%), and increased fill factor (0.66 to 0.70). For larger size Pt NPs of 3.45 nm, the composite photoelectrode produced a lower photocurrent and reduced conversion efficiency compared to the pristine TiO(2) electrode. However, the surface modification by Pt NPs helped the composite electrode maintain higher fill factor values.     

基于铝离子掺杂二氧化钛薄膜的染料敏化太阳能电池的光电性能

采用水热法制备出Al3+掺杂二氧化钛薄膜,通过玻璃棒涂于导电玻璃上,在450°C的温度下烧结并将其用N3染料敏化制成染料敏化太阳能电池(DSSCs).通过X射线光电子能谱(XPS)、X射线衍射(XRD)、扫描电镜(SEM)及DSSCs测试系统对其进行了测试表征,研究了Al3+掺杂对TiO2晶型及染料敏化太阳能电池的光电性能影响.XPS数据显示Al3+成功掺杂到了TiO2晶格内,由于Al3+的存在,对半导体内电子和空穴的捕获及阻止电子/空穴对的复合发挥重要作用.莫特-肖特基曲线显示掺杂Al3+后二氧化钛平带电位发生正移,并导致电子从染料注入到TiO2的驱动力提高.DSSCs系统测试结果表明,Al3+掺杂的TiO2薄膜光电效率达到6.48%,相对于无掺杂的纯二氧化钛薄膜光电效率(5.58%),其光电效率提高了16.1%,短路光电流密度从16.5mA·cm-2提高到18.2mA·cm-2.     

聚3-氯噻吩修饰CdSe纳米棒复合膜电极光电化学性能研究

采用水热法制备了具有闪锌矿和纤维锌矿结构的CdSe纳米棒. 纳米棒直径约为100 nm, 长度约为300 nm. 当外加电极电势为-0.6 V 时, 经聚3-氯噻吩[Poly(3-chlorothiophene), P3CT]修饰的CdSe纳米棒具有最大光电流, 并且CdSe/P3CT复合膜电极最高光电转换效率(IPCE)为13.5%, 低于CdSe纳米棒膜电极17.7%的最高IPCE. CdSe/P3CT复合膜电极中存在p-n异质结, p-n异质结的存在使得CdSe/P3CT复合膜电极在长波区(>410 nm)的IPCE整体高于CdSe纳米棒薄膜电极的IPCE.     

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     

纳米尺度TiO2聚苯胺多孔膜电极光电化学研究

用光电流作用谱，光电流－电势图等光电化学方法研究了ＴｉＯ２／聚本胺复合多孔膜电极在不含氧化还原和含有没氧化还原对体系中的光电转换过程。结果说明，ＴｉＯ２／聚苯胺复合多孔膜电极为双层ｍ－型半导体结构，ＴｉＯ２多孔膜的禁带宽度为３．２ｅＶ，外层聚苯胺膜的禁带宽度为２．８８ｅＶ。     

可见光响应Bi2WO6薄膜的制备与光电化学性能

采用非晶态配合物-提拉法在ITO导电玻璃基底上制备得到Bi2WO6薄膜. 采用FE-SEM、XRD、Raman、DRS、光电流响应谱、IPCE等手段, 研究了Bi2WO6薄膜的形貌、结构、光电性能以及薄膜结构与光电性能的关系. 结果表明, 450 ℃以上煅烧可以得到Bi2WO6结晶薄膜, 薄膜由沿(131)晶面趋向生长的Bi2WO6纳米颗粒组成, 颗粒的粒度随煅烧温度的升高而增大, 同时颗粒之间的间距也相应增大. ITO/Bi2WO6薄膜电极在可见光(λ>400 nm)照射下可以产生光电流, 光电流强度与光强度线性相关; 光电流强度和光电转换量子效率受Bi2WO6薄膜结构的影响, 通过控制薄膜的煅烧温度等制备条件, 可以提高薄膜光电极的光电转换量子效率.     

Influence of Modification of Counter Electrode on Photoelectric Properties of Dye-sensitized TiO2 Solar Cells

A dye-sensitized nanocrystalline TiO2 solar cell(DYSC) was assembled, of which counter electrode was modified already by platinum, nickel and carbon. It was found that the DYSC had better photoelectric performance when the electrode was modified by platinum than by nickel and carbon. The influence of the incidence light wavelength on the incidence monochromatic photoelectric conversion effieieney(IPCE) was investigated.The result shows that the IPCE mainly depends on the short-circuit current density(Isc) of a DYSC, and the IPCE reaches 48.32% under the irradiation with the wavelength of 560 nm when the counter electrode of a DYSC was modified by platinum. The influence of incident light intensity on the photoelectric properties of a DYSC was also investigated. It was found that the Isc and open-circuit voltage(Voc) increased and the fill factor(ff) of the DYSC decreased with the increase of the incident light intensity.