表面活性剂对染料敏化太阳能电池光电性能的提高

在硝酸/醋酸(HNO₃/HAc)的水溶液中分别加入十二烷基苯磺酸钠(DBS)、十六烷基三甲基溴化铵(CTAB)、吐温20等不同类型的表面活性剂来水解钛酸四正丁酯制得前驱体溶液,通过水热法制备纳晶TiO₂,并组装成染料敏化太阳能电池(DSSC)。通过XRD、SEM和UV-Vis对纳晶TiO₂薄膜进行表征,并对DSSC进行光电流-光电压(I-V)曲线的测试,研究了不同类型的表面活性剂和不同浓度的CTAB对DSSC光电性能的影响。结果表明：加入阳离子表面活性剂CTAB时提高了DSSC的光电性能,而加入阴离子表面活性剂DBS和非离子表面活性剂吐温20时,DSSC的光电性能反而降低。随着CTAB浓度的增加,电池的光电性能先提高后下降,当c_CTAB=0.08 mol·L^-1时,DSSC的光电转化效率最高为5.76%,比不添加表面活性剂制备的纳晶TiO₂所组装的DSSC的光电转化效率提高了约18%。     

TiO2纳米微球的制备及在染料敏化太阳能电池中的应用

以四氯化钛、盐酸为原料,制备出花状TiO₂纳米微球,利用扫描电子显微镜（SEM）、X射线衍射（XRD）等测试方法,对样品的结构和形貌进行了表征。为了提高TiO₂微球电池的光电性能,利用TiO₂微球作为反射层构造了双层结构的薄膜电极,结果表明,双层结构染料敏化太阳能电池在100 mW·cm^-2（1.5 G）光照条件下,短路光电流J_sc为17.64 mA·cm^-2,开路光电压Voc为0.74 V,填充因子FF为0.63和光电转化效率η为8.33%。相比TiO₂微球制备的太阳能电池,双层结构染料敏化太阳能电池光电转化效率提高至5.3倍。最后对电极中染料的吸附量、电极的光散射性能和电池的电化学阻抗做了进一步研究和分析,研究表明,双层结构电池增强光的捕获能力,从而提高光伏性能。     

骨架结构多孔TiO2薄膜增强染料敏化太阳能电池性能

以空心球状TiO₂为基体、以片状TiO₂为骨架,采用刮刀法制备了染料敏化太阳能电池的多孔TiO₂光阳极薄膜。光电转化效率测试结果表明,当作为骨架支撑材料的片状TiO₂含量为20wt%时,光阳极薄膜组装成太阳能电池的光电转化效率达到最高值4.53%,比商业P₂₅制备的无孔无骨架TiO₂薄膜电池(4.06%)及无骨架结构的多孔TiO₂薄膜电池(4.17%)的性能均有显著提高。当片状TiO₂的最佳含量为20wt%电池薄膜厚度为33μm时,太阳能电池光电转化效率进一步提升为7.06%。光电性能增强的原因是骨架结构有利于快速传输电子并增大染料吸附量。本研究通过设计制备具有骨架结构的多孔TiO₂薄膜为提高染料敏化太阳能电池性能提供了新的思路。     

骨架结构多孔TiO2薄膜增强染料敏化太阳能电池性能

以空心球状TiO₂为基体、以片状TiO₂为骨架,采用刮刀法制备了染料敏化太阳能电池的多孔TiO₂光阳极薄膜。光电转化效率测试结果表明,当作为骨架支撑材料的片状TiO₂含量为20wt%时,光阳极薄膜组装成太阳能电池的光电转化效率达到最高值4.53%,比商业P25制备的无孔无骨架TiO₂薄膜电池(4.06%)及无骨架结构的多孔TiO₂薄膜电池(4.17%)的性能均有显著提高。当片状TiO₂的最佳含量为20wt%电池薄膜厚度为33 μm时,太阳能电池光电转化效率进一步提升为7.06%。光电性能增强的原因是骨架结构有利于快速传输电子并增大染料吸附量。本研究通过设计制备具有骨架结构的多孔TiO₂薄膜为提高染料敏化太阳能电池性能提供了新的思路。     

纳米级TiO2粉体的制备研究——Ⅱ.絮凝剂及其浓度的影响

采用溶胶-凝胶-超临界流体干燥(SCFD)法制备纳米级TiO₂超细粉，详细考察了不同絮凝剂及其浓度对TiO₂织构和结构性质的影响。结果表明，利用强碱溶液作为絮凝剂，浓度为5 mol·L^-1是制备大孔高比表面TiO₂超细粉较为适宜的条件。     

纳米TiO2介孔薄膜的模板组装制备研究

以TiCl₄为无机前驱体、三嵌段高分子共聚物EO₂₀PO₇₀EO₂₀为模板剂，在非水条件下制备了有序的锐钛矿TiO₂纳米晶介孔薄膜。通过热重-差热（TG-DTA）分析、X射线衍射（XRD）分析、原子力显微观察（AFM）及N₂吸附-脱附等测试对样品进行了表征。结果表明，薄膜具有均一的大介孔孔径（～10 nm），其BET比表面积为150 m²·g^-1，薄膜较宽的无机壁厚显著提高了介孔结构的热稳定性。通过红外（IR）光谱分析考察了溶胶-凝胶过程中发生的物理化学变化。在对薄膜表面形貌进行AFM观察的基础上初步探讨了嵌段共聚物EO₂₀PO₇₀EO₂₀对薄膜孔结构形成的导向机理。     

TiO2纳米棒和CdSe纳米棒复合膜与聚3-甲基噻吩杂化太阳能电池研究

采用水热法制备了TiO₂和CdSe两种纳米棒材料, 将两种纳米材料制备成TiO₂/CdSe复合纳米棒膜电极, 并在复合膜上电化学聚合生成聚3-甲基噻吩poly(3-methylthiophene) (PMeT), 研究了其光电化学性能. 实验表明, 当TiO₂与CdSe的物质的量复合比为2∶1, PMeT的聚合时间为40 s, 在电极电势为－0.2 V下ITO/TiO₂/CdSe/PMeT电极光电转换效率(IPCE)达到56%, 对比ITO/TiO₂/CdSe复合膜电极在长波方向的光电转换效率明显提高, 光吸收截止波长发生了明显的红移. 同时以ITO/TiO₂/CdSe/PMeT组装了简易的杂化太阳电池, 初步研究了光电池性能, 光电池总效率为0.08%, V_oc＝0.4 V, j_sc＝0.61 mA/cm², ff＝0.33.     

表面In掺杂TiO2的N719/TiO2-Inx%/FTO薄膜电极的光电转换效率

采用溶胶-凝胶法制备出In 表面修饰的TiO₂ (TiO₂-Inx%)纳米粒子, x%代表在In 掺杂的TiO₂样品中In³⁺与In³⁺和Ti⁴⁺离子摩尔百分含量. 利用二(四丁基铵)顺式-双(异硫氰基)双(2,2''-联吡啶-4,4''-二羧酸)钌(II)(N719)作为敏化剂, 制备出N719/TiO₂/FTO (氟掺杂锡氧化物)和N719/TiO₂-Inx%/FTO染料敏化薄膜电极. 光电转换效率实验表明, 在薄膜电极+0.5 mol·L^-1 LiI+0.05 mol·L^-1 I₂的三甲氧基丙腈(MPN)溶液+Pt 光电池体系中,N719/TiO₂-Inx%/FTO薄膜电极的光电转换效率均高于N719/TiO₂/FTO, 其中N719/TiO₂-In0.1%/FTO的光电转换效率比N719/TiO₂/FTO提高了20%. 利用X 射线衍射(XRD)、X 射线光电子能谱(XPS)、漫反射吸收光谱(DRS)、荧光(PL)光谱和表面光电流作用谱确定了TiO₂-Inx%样品中In3+离子的存在方式和能带结构; 利用表面光电流作用谱研究了N719/TiO₂-Inx%/FTO薄膜电极的光致界面电荷转移过程. 结果表明, In3+离子在TiO₂表面形成O-In-Cl_n (n=1, 2)物种, 该物种的表面态能级位于导带下0.3 eV处; 在光电流产生过程中, O-In-Cl_n (n=1, 2)表面态能级有效地抑制了光生载流子在TiO₂-Inx%层的复合, 促进了阳极光电流的增加, 从而导致N719/TiO₂-Inx%/FTO薄膜电极的光电转化效率高于N719/TiO₂/FTO, 并进一步讨论了光致界面电荷转移的机理.     

表面修饰的TiO_2太阳能电池界面特性研究

用水热法制备了具有典型锐钛矿晶型的TiO2纳米材料,采用Cr(NO3)3对TiO2薄膜电极进行修饰改性。用X射线衍射(XRD)、扫描电子显微镜(SEM)和光电子能谱(XPS)测试电极的物相及表面结构,结果显示TiO2薄膜表面包覆一层粒径较大的氧化铬颗粒,整个电极仍保持均匀的多孔结构。电流-电压(I-V)曲线测试结果显示,改性后最佳电极的短路电流和光电转换效率分别比改性前提高了31.1%和40.4%。用电化学阻抗谱(EIS)测试电池的界面特性,从测试结果可以看出,相同偏压下,改性后电池的TiO2/染料/电解质界面电阻更大,说明氧化铬包覆层在一定程度上抑制了界面的电子复合,改善了电池的光电输出特性。     

水热法制备TiO_2纳米线薄膜的光生阴极保护性能

应用水热法在钛箔表面制备TiO2纳米线薄膜,采用场发射扫描电子显微镜、X射线衍射和紫外-可见分光光度法对薄膜进行表征,用电极电位和电化学阻抗谱考察TiO2光生阴极保护性能.结果表明:薄膜由纵横交错的锐钛矿型TiO2纳米线组成,纳米线的直径约10nm.在150℃下反应6h生成的TiO2纳米线薄膜在0.3mol·L-1 Na2SO4溶液和0.3mol·L-1 Na2SO4+0.5mol·L-1 HCOOH混合溶液中对与TiO2薄膜耦连的403不锈钢均有良好的阴极保护效应.TiO2膜所在溶液中含有HCOOH时,可使耦连的403不锈钢在0.5mol·L-1 NaCl溶液中电极电位负移约545mV,界面反应电阻显著变小,表明电解质溶液加入HCOOH可以增强TiO2纳米线薄膜对403不锈钢的光生阴极保护效应.     

Characterization of Nano‐porous TiO2 Film Prepared by Sol‐gel Process and Its Application to Dye‐sensitized Solar Cell

In this paper, effects of ethylene glycol (EG) and indium tin oxide (ITO) solution on the morphology, porosity, and roughness of TiO₂ film prepared by sol‐gel process were investigated and discussed. Initially, the addition of EG were used to control the viscosity of the solution and it was found to increase the pore size of TiO₂ film. The various TiO₂ films were investigated and characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) and then assembled to dye‐sensitized solar cell (DSSC) to measure the photoelectric conversion efficiency. The optimum efficiencies of 1.32% with J_sc and V_oc of 2.99 mA/cm² and 0.80 V, respectively, were obtained by the TiO₂ film prepared from a solution containing 20 wt% EG.     

Evaluating the electrochemical properties of PEO‐based nanofibrous electrolytes incorporated with TiO2 nanofiller applicable in lithium‐ion batteries

In the present work, nanofibrous composite polymer electrolytes consist of polyethylene oxide (PEO), ethylene carbonate (EC), propylene carbonate (PC), lithium perchlorate (LiClO₄), and titanium dioxide (TiO₂) were designed using response surface method (RSM) and synthesized via an electrospinning process. Morphological properties of the as‐prepared electrolytes were studied using SEM. FTIR spectroscopy was conducted to investigate the interaction between the components of the composites. The highest room temperature ionic conductivity of 0.085 mS.cm^?1 was obtained with incorporation of 0.175 wt. % TiO₂ filler into the plasticized nanofibrous electrolyte by EC. Moreover, the optimum structure was compared with a film polymeric electrolyte prepared using a film casting method. Despite more amorphous structure of the film electrolyte, the nanofibrous electrolyte showed superior ion conductivity possibly due to the highly porous structure of the nanofibrous membranes. Furthermore, the mechanical properties illustrated slight deterioration with incorporation of the TiO₂ nanoparticles into the electrospun electrolytes. This investigation indicated the great potential of the electrospun structures as all‐solid‐state polymeric electrolytes applicable in lithium ion batteries.     

Study of quasi-solid electrolyte in dye-sensitized solar cells using surfactant as pore-forming materials in TiO<Subscript>2</Subscript> photoelectrodes

A novel polymer gel electrolyte was used to improve the performance and long-term stability in dye-sensitized solar cells (DSSCs). The polymer gel electrolyte (PGE) was prepared by mixing 5 wt% poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and 2 % TiO₂ nanoparticles. The conductivity of PGE with P25 reached 9.98 × 10^?3 S/cm, which increased by 34.9 % compared with 7.40 × 10^?3 S/cm of PGE without P25, and the diffusion coefficient was also increased by 19.0 %. Different photoelectrodes were obtained by using three kinds of surfactants (cetylamine, octadecylamine, and P123) as pore-forming materials, and their morphologies were contrasted through scanning electron microscopy (SEM). The results showed that gel electrolyte can increase the short-circuit current density (J _sc) from 11.01 to 12.99 mA/cm² in DSSCs. Moreover, unlike the liquid electrolyte, the gel electrolyte is more conducive to the TiO₂ photoelectrodes with larger pores. In conclusion, the efficiency of DSSC with gel electrolyte and P123 as pore-forming material was 6.73 %, which was 12 % higher than the liquid electrolyte in the same test condition. In addition, the sealed gel electrolyte DSSCs showed better stability than did liquid electrolyte DSSCs during nearly 600 h.     

Preparation of TiO2 nanocrystalline films controlled by acetylacetone/polyethylene glycol and their photoelectric properties

TiO₂ nanocrystalline films were prepared from titanium tetra-n-butoxide modified with double hydrolysis inhibitors, acetylacetone and polyethylene glycol (PEG), in mixture of methanol and ethanol. The correlation among surface structure of the TiO₂ films, preparation conditions, and photovoltaic properties of the solar cells using the TiO₂ films was investigated. The particle size of the obtained TiO₂ films was decreased as the PEG content increased. The nanostructured films with the narrow distribution of particle size could be prepared. The amounts of adsorbed dyes for these TiO₂ films were larger than that without PEG. The performance of the solar cell fabricated using the TiO₂ film improved as the amount of the PEG increased, and the solar cell using the TiO₂ film prepared from the solution with 30 wt% PEG exhibited the highest performance.