利用强度调制光电流谱研究TiO2薄膜中染料不均匀分布现象

利用强度调制光电流谱(IMPS)研究了不同微结构的TiO2薄膜在不同的浸泡时间条件下的染料分布情况, 分析了染料分布对染料敏化太阳电池光伏性能的影响. 研究结果表明, TiO2薄膜中确实存在染料的不均匀分布现象, 染料不均匀分布对太阳电池的光伏性能有显著的影响.     

单晶二氧化钛纳米棒阵列的修饰及其在量子点敏化太阳电池中的应用(英文)

使用TiCl4溶液对单晶TiO2纳米棒阵列(TNRs)进行修饰,通过在TiO2纳米棒表面合成TiO2纳米颗粒来提高TNRs的表面积,提高TNRs对量子点的吸附能力,并在此基础上研究了TiCl4修饰时间对基于单晶TNRs的CdS/CdSe量子点敏化太阳电池光伏性能的影响,同时结合强度调制光电流谱(IMPS)研究了TiO2纳米棒阵列的电子传输性能.结果表明:TiCl4修饰可以大幅提高基于单晶TNRs的CdS/CdSe量子点敏化太阳电池的光伏性能,在TiCl4修饰时间为60 h时,其短路电流密度和光电转换效率分别由修饰前的(2.93±0.07)mA·cm-2和0.36%±0.02%提高至(8.19±0.12)mA·cm-2和1.17%±0.07%.同时,IMPS测试表明电子在单晶TiO2纳米棒阵列中的传输速率高于在TiO2纳米颗粒薄膜中的传输速率,证明了单晶TiO2纳米棒阵列在电子传输方面的优越性.     

染料敏化太阳电池中双层结构TiO2薄膜空间的电子分布与接触界面转移过程

采用电化学阻抗谱(EIS)研究了双层结构TiO2薄膜的电子积累和与电解液接触界面的电子转移过程. 通过制备纳米颗粒单层和纳米颗粒/亚微米颗粒双层2种不同微结构的TiO2薄膜电极, 对其电容分布、 局域态密度、 薄膜内部电子传输和固/液界面电子转移过程进行了研究. 分析了纳米颗粒/亚微米颗粒双层结构电极对染料敏化太阳电池(DSC)性能的影响. 结果表明, 一定数量的电子会积累在亚微米颗粒层中引起薄膜电极化学电容的增加. 在纳米颗粒层上端覆盖亚微米颗粒后降低了界面复合电阻, 但对薄膜电极的传输性能影响较小. 因此在筛选和制备DSC散射层材料时除应具有良好的光散射性能外, 还应考虑材料的化学电容和界面转移电阻等因素.     

二氧化钛在钙钛矿太阳电池中的应用

纳米TiO₂由于具有合适的禁带宽度、良好的光电化学稳定性、制作工艺简单等特点,目前广泛应用于染料敏化、量子点和钙钛矿等太阳电池中。作为电池的重要组成部分之一,纳米TiO₂晶体尺寸、颗粒大小和制备方法等明显影响电池的光伏性能,相关研究工作一直是染料敏化、量子点和钙钛矿等太阳电池方面的重点。本文综述了纳米TiO₂作为致密层和骨架层在钙钛矿太阳电池中的应用研究进展,主要讨论了纳米TiO₂的不同形貌、制备方法以及结构等对电池光电性能的影响,并针对纳米TiO₂在后续对电池性能提升方面进行了展望。     

染料敏化纳米薄膜太阳电池中的染料敏化剂

简要介绍了化学太阳电池的原理和染料敏化剂的发展历史,将现有染料敏化纳米薄膜太阳电池(简称DSCs)中的染料敏化剂分为有机和无机两大类,详细介绍了其中的羧酸多吡啶钌、膦酸多吡啶钌、多核联吡啶钌染料和有机染料的研究进展;介绍了其它染料敏化剂和多种染料协同敏化的研究现状;评述了染料敏化剂在染料敏化纳米薄膜太阳电池中应用的研究进展。     

温度对不同电解质的大面积DSCs电池性能的影响

从实验和理论上探讨了温度对染料敏化纳米薄膜太阳电池性能的影响.初步研究了其性能随温度的变化规律.在解决液体电解质染料敏化纳米薄膜太阳电池的基础上,利用乙醇作为冷冻液,通过控制冷冻液的温度来恒温电池的温度,模拟制作了实用化电池,其尺寸(15cm×20cm)基本接近实用化.     

4.81%光电转换效率的全固态致密PbS量子点薄膜敏化TiO_2纳米棒阵列太阳电池（英文）

利用TiO_2纳米棒阵列和在旋涂辅助连续离子层吸附反应过程中使用乙二硫醇的策略,成功地在TiO_2纳米棒阵列上获得了致密PbS量子点薄膜,组装了新颖结构的全固态致密PbS量子点薄膜敏化TiO_2纳米棒阵列太阳电池。研究了TiO_2纳米棒阵列长度对全固态致密PbS量子点薄膜敏化太阳电池光伏性能的影响,发现TiO_2纳米棒阵列长度为290、540和1040 nm时,相应太阳电池的光电转换效率分别是2.02%、4.81%和1.95%。对于组装全固态量子点敏化太阳电池,综合考虑空穴传输长度和量子点担载量的平衡是获得较高光电转换效率的关键所在。     

电泳法制备具有{001}面TiO2纳米片分级球散射层的染敏太阳电池光电极

利用简便的溶剂热法,制得了由锐钛矿相的纳米片组成的、{001}面接近100%暴露的TiO2分级球形结构。利用电泳沉积法,将所得的TiO2分级球形结构作为散射层引入到染料敏化太阳电池(DSSC)中,并很好地保护了这种脆弱的分级结构。由于这种分级球形结构比TiO2纳米颗粒具有更好的染料吸附性能和光散射性能,使用这种TiO2分级球形结构作为散射层的DSSC达到了7.38%的光电转换效率,较之基于TiO2纳米颗粒的DSSC有了26%的提高。     

染料敏化La~(3+)掺杂的TiO_2纳晶薄膜制备及其光电性能

采用溶胶-凝胶法制备出La3+掺杂的TiO2纳米粉体材料,通过料浆喷涂工艺制得掺杂La3+的TiO2薄膜并将其以N719染料敏化制成染料敏化太阳能电池(DSSC)。以X射线衍射(XRD)、扫描电镜(SEM)和DSSC测试系统对制得的La3+掺杂的TiO2纳米粉体材料、相应的La3+掺杂的TiO2薄膜以及制成的DSSC分别进行测试表征,研究了La3+掺杂对TiO2晶型和染料敏化太阳能电池性能的影响。XRD测试结果表明,La3+的掺杂改善了TiO2的颗粒分布;电池的测试结果说明,La3+掺杂量为0.5%,煅烧温度为450℃时制备的纳米TiO2膜DSSC电池性能最佳,光电转换效率达1.926%。     

染料敏化纳米薄膜太阳电池中离子液体基电解质的研究进展

综述了离子液体基电解质在染料敏化纳米薄膜太阳电池中的研究及应用进展，详细论述了多种离子液体基电解质系统对染料敏化纳米薄膜太阳电池性能的影响，并比较了这些系统的优缺点. 根据胶凝剂的不同分别论述了离子液体基电解质的固化及其对电池性能的影响. 评述了离子液体基电解质在大面积电池中的应用，并对离子液体基电解质未来发展方向进行了展望.     

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.     

Low-temperature formation of efficient dye-sensitized electrodes employing nanoporous TiO2 spheres

300-nm-sized nanoporous TiO₂ spheres (SPs), blended with 25-nm-sized nanoparticles, were successfully applied to low-temperature fabrication of TiO₂ electrodes for dye-sensitized solar cell (DSC). The introduction of SPs increased the adsorbed amount dye molecules, induced the efficient transport of photo-injected electrons through TiO₂ layer, and offered an extended light-scattering efficiency in the long wavelength region. Furthermore, the adhesion of TiO₂ layer to the FTO substrate was considerably improved. As a result, the photovoltaic conversion efficiency (η) of DSC processed at 140 °C was enhanced from 4.4% to 6.3%.     

二氧化钛膜参数对离子液体基染料敏化纳米薄膜太阳电池性能的影响

Photo correlation spectroscopy was used to measure the particle size distribution of TiO2 films. Other parameters, such as porosity, BET surface area, average pore size, crystallite size D101, distribution of pore size etc. were also measured. The effects of these parameters on the ionic liquid based dye-sensitized solar cells （DSC） were studied. It was concluded that the particle size distribution of nanocrystalline TiO2 played an important role on the performance of DSC. The narrow particle size distribution of nanocrystalline TiO2 increased the efficiency of DSC, while the wide distribution decreased the efficiency of DSC. From the result above, it was also concluded that the photo correlation spectroscopy was a good method to identify the performance of TiO2 films. Based on electrochemical impedance spectroscopy, we found that the particle size distribution could affect the electronic contact between the TiO2 layers as well. The narrow particle size distribution made the electronic contact between TiO2 layers better than the wide particle size distribution of the TiO2 films, and then better the electronic contact, higher the efficiency of the DSC.     

化学浴沉积方法制备硫化铟敏化太阳电池及其性能研究

硫化铟是一种稳定、低毒性的半导体材料. 本文采用低成本的化学浴沉积方法制备了硫化铟敏化太阳电池, X射线衍射(XRD)、光电子能谱(XPS)和扫描电镜(SEM)结果表明形成了硫化铟敏化的二氧化钛薄膜. 化学浴沉积温度对所得硫化铟敏化薄膜的形貌有显著的影响, 进而影响电池性能. 温度太低时, 化学浴沉积反应速率太低, 只发生少量沉积; 温度太高时, 化学浴沉积反应速率较快, 硫化铟来不及沉积到二氧化钛多孔薄膜内部. 当温度在40℃时, 硫化铟沉积均匀性最好, 薄膜的光吸收性能最佳, 电池的短路电流最大, 另外, 填充因子达到最佳, 为65%, 电池总体光电转换效率为0.32%.     

Surface properties and photocatalytic activity of nanocrystalline titania films

In this work the efficiency and physicochemical details of a thin film produced by help of a microwave assisted sol gel technique is compared to different commercial powders (Degussa P25 and Hombikat UV100) deposited on glass substrates. Furthermore, a supercritical produced TiO₂ powder (SC 134) was included in the comparison.The prepared TiO₂ films were characterized using XRD, XPS, AFM, DSC and DLS. The photocatalytic activity was determined using stearic acid as a model compound. Investigation of the prepared films showed that the Degussa P25 film and the sol–gel film were the most photocatalytic active films. The activity of the films was found to be related to the crystallinity of the TiO₂ film and the amount of surface area and surface hydroxyl groups. Based on the XPS investigation of the films before and after UV irradiation it was suggested that the photocatalytic destruction of organic matter on TiO₂ films proceeds partly through formation of hydroxyl radicals which are formed from surface hydroxyl groups created by interactions between adsorbed water and vacancies on the TiO₂ surface. Furthermore a correlation between the amount of OH groups on the surface of the different TiO₂ films and the photocatalytic activity was found.     

A Dewetted‐Dealloyed Nanoporous Pt Co‐Catalyst Formed on TiO2 Nanotube Arrays Leads to Strongly Enhanced Photocatalytic H2 Production

Pt nanoparticles are typically decorated as co‐catalyst on semiconductors to enhance the photocatalytic performance. Due to the low abundance and high cost of Pt, reaching a high activity with minimized co‐catalyst loadings is a key challenge in the field. We explore a dewetting‐dealloying strategy to fabricate on TiO₂ nanotubes nanoporous Pt nanoparticles, aiming at improving the co‐catalyst mass activity for H₂ generation. For this, we sputter first Pt‐Ni bi‐layers of controllable thickness (nm range) on highly ordered TiO₂ nanotube arrays, and then induce dewetting‐alloying of the Pt‐Ni bi‐layers by a suitable annealing step in a reducing atmosphere: the thermal treatment causes the Pt and Ni films to agglomerate and at the same time mix with each other, forming on the TiO₂ nanotube surface metal islands of a mixed PtNi composition. In a subsequent step we perform chemical dealloying of Ni that is selectively etched out from the bimetallic dewetted islands, leaving behind nanoporous Pt decorations. Under optimized conditions, the nanoporous Pt‐decorated TiO₂ structures show a>6 times higher photocatalytic H₂ generation activity compared to structures modified with a comparable loading of dewetted, non‐porous Pt. We ascribe this beneficial effect to the nanoporous nature of the dealloyed Pt co‐catalyst, which provides an increased surface‐to‐volume ratio and thus a more efficient electron transfer and a higher density of active sites at the co‐catalyst surface for H₂ evolution.     

Electrochemical preparation of PMeT/TiO<Subscript>2</Subscript> nanocomposite electrochromic electrodes with enhanced long-term stability

In this work, 3-methylthiophene (MeT) was electrochemically incorporated with nano- and mesoporous TiO₂ films to form poly(3-methylthiophene) (PMeT)/TiO₂ nanocomposite electrochromic electrodes. TiO₂ films, which were previously coated on the ITO glass sheets through a well-established technique, were introduced to enhance the adhesion of the polymers to the substrates and thus increase the long-term stability of the devices. With this effort, the nanocomposite electrodes were found to retain up to 60% of their optical response after 3,500 deep and double potential steps and retain up to 50% of their electroactivity after 10⁴ same steps, exhibiting enhanced long-term stability. Switching time and the maximum optical contrast (ΔT%) of the nanocomposite electrodes were found to be 0.6 s and 45%, respectively. Moreover, our work showed that electrochemically incorporating conductive polymers (CPs) with TiO₂ mesoporous films was an effective method to form high-quality CP/TiO₂ nanocomposite electrodes, which can be used widely in battery cathodes, photovoltaic cells, photocatalytic reaction, and photoelectrochromic cells and were supposed to enhance their performances.     

染料敏化太阳电池中TiO2/染料/电解质界面的修饰

染料敏化太阳电池(DSC)作为新型太阳电池自问世以来受到了广泛关注, 其系统内部的接触界面尤其是TiO₂/染料/电解质界面一直是该领域的研究热点. 光敏染料的吸附以及电子的注入、传输和复合都发生在该界面, 其界面性质对DSC性能具有很大影响. 对染料敏化太阳电池中TiO₂/染料/电解质界面进行修饰可以有效抑制染料聚集和电子复合, 提高电子的注入效率与传输速率; 同时, 对TiO₂导带边的位置及染料吸附等也产生一定的影响, 最终提高电池的光电转换效率和稳定性. 本文主要从不同的修饰途径详细评述了TiO₂/染料/电解质界面修饰方法及机理研究进展,包括TiO₂光阳极的修饰改性、染料溶液中共吸附剂的引入和多种染料共敏化处理以及电解质中不同功能添加剂的应用. 指出了这些修饰方法目前存在的主要问题, 并对未来的发展方向进行了展望.     

Tuning Structural Colors of TiO2 Thin Films Using an Electrochemical Process

TiO₂ films exhibiting structural colors were successfully prepared using one-step electrochemical oxidation. Results of theoretical analyses and digital simulations revealed that the structural color of a TiO₂ thin film could be regulated by adjusting oxidation voltage and oxidation time with different oxidation voltages leading to changes in structural color annulus number. At a low oxidation voltage, each thin film exhibited a single structural color, while thin films with different structural colors were obtained by varying the oxidation time. By contrast, at a higher oxidation voltage, each film exhibited iridescent and circular structural color patterns associated with symmetrical decreases in surface oxidation current density along radial lines emanating from the film center to its outer edges. TiO₂ films exhibiting iridescent structural colorations have broad application prospects in industrial fields related to photocatalysis and photovoltaic cells.