以芳胺为电子给体的D-π-A有机光敏染料———— 染料敏化太阳电池中的应用*

不含金属的有机染料在染料敏化太阳电池（DSC）中的应用愈加广泛,以芳胺为电子给体的D-π-A分子是其中重要的一类。本文依据芳香胺的结构,将近5年来应用于DSC中一百多个D-π-A分子分成四类,包括：基于N-烷基-苯胺的D-π-A光敏染料,基于三苯胺的D-π-A光敏染料,由包含芴基团的三芳胺构建的D-π-A光敏染料,包含芳胺基团的其它结构类型的D-π-A光敏染料。评述了它们的光电转换性能。     

新型D-π-A类敏化太阳电池染料及其应用

功能性有机染料在染料敏化太阳能电池领域具有重要的应用前景,电子给体、π共轭桥和电子受体（D-π-A）结构的染料是其中重要的组成类型.本文主要依据三苯胺和吲哚啉等取代苯胺为电子给体染料的结构设计,并结合本课题组的相关工作,综述了2008年以来此类D-π-A光敏染料的光电转换性能的研究进展.     

染料敏化太阳能电池中二聚噻吩类光敏染料构效关系的理论研究

D-π-A型有机光敏染料结构上的微小差异会引起器件性能的显著不同. 为了合理解释染料分子1和2(给体分别为咔唑和二氢吲哚)结构与性能之间的关系, 采用密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)讨论了包括紫外-可见吸收光谱、 光捕获效率、 电子注入驱动力、 垂直方向偶极矩和电子转移数目在内的一系列影响染料性能的理论参数. 结果表明, 在光捕获效率和电子注入效率差别不大的情况下, 染料分子2较低的染料再生效率可导致其短路电流较小; 同时, 在由光诱导产生的从染料分子转移到半导体的电子数目以及电子复合程度相差不大的情况下, 染料分子1垂直方向上较大的偶极矩则可导致其具有较高的开路电压. 计算结果与实验值相吻合, 有望对今后设计合成高效光敏染料提供一定的理论指导.     

双链结构有机光敏染料的合成及性能

设计合成了2个含双D-π-A结构的新型有机光敏染料DP1和DP2,利用高分辨质谱(HRMS)、核磁共振氢谱及核磁共振碳谱对其结构进行了表征。 研究了2个染料的光物理和电化学性质,并将其应用于染料敏化太阳能电池(DSSCs)的制作中。 在100×10-3 W/cm2(AM 1.5) 模拟太阳光的照射下,由染料DP2所制备的敏化太阳能电池的光电转化效率为4.10%;开路电压(Voc)、短路电流密度(Jsc)和填充因子(FF)分别为0.63 V、8.59×10-3 A/cm2和0.76。 而在同等条件下,由染料DP1所制作的染料敏化电池光电转化效率为3.83%。     

新型复合及叠层染料敏化太阳电池研究

染料敏化太阳电池（DSC,染敏电池）是一种新型光伏电池.为了进一步提高染敏电池的光电转化效率,以提高太阳光利用率、拓宽电池整体吸收为切入点,主要研究了三种叠层染敏电池及自主开发的一种基于膜转移技术的新型复合染敏电池.首先对三种叠层染敏电池的性质、不同结构中顶层及底层电池效率的影响因素进行了系统研究.其次对新型复合染敏电...     

染料敏化太阳能电池敏化剂的模块化设计理念*

作为第一个开创性的分子光伏太阳能器件,染料敏化太阳能电池(DSSC)由于其低成本、可调节性和高光伏性能而引起了全世界的广泛关注。 随着用于DSSC的纯有机敏化剂的发展,其构型从D-π-A、D₂-π-A到D-A-π-A,逐渐形成了完整的模块化设计理念。 依据该理念,研究者完成了大量具有高光伏性能的有机敏化剂的设计和合成,并应用到DSSC中。为了将分子新能源的前沿领域引入化学专业本科生的专业课程,在此总结了敏化剂的模块化设计思路及应用,以满足化学专业相关课程的要求,同时以提高学生的学习兴趣和知识范围。 模块化设计理念可操作性强,可大幅提高工作效率,有望应用于分子设计的其他领域。     

近红外吸收菁染料分子链结构对其光氧化稳定性能的影响

本文对具有不同分子链结构及不同链长,而母核结构分别为吲哚类及喹啉类的六种菁染料在溶液中的光氧化稳定性能进行了研究。结果表明菁染料的光褪色主要是由光氧化反应所致,当在分子链上引入不饱和环体结构时,可以使菁染料分子的光稳定性能增加;而随着分子链长的增加菁染料的光氧化稳定性能则明显下降。通过顺磁共振谱测定结果表明,在菁染料的自敏光氧化反应原初过程中,既存在单重态氧过程又存在超氧负离子过程。     

2种三聚茚基三芳胺染料的合成及其光伏性能

以三聚茚基三芳胺为给电子单元,以绕单宁-3-乙酸为受电子单元,设计合成了2种三聚茚基三芳胺染料六乙基三聚茚胺饶丹宁乙酸(MXD8)和六乙基三聚茚胺环氧噻吩饶丹宁乙酸(MXD9)。 光学测试表明,该类染料光谱响应范围宽,摩尔吸光系数高。 结合2种染料的紫外-可见光谱和循环伏安曲线,确定了染料的电子基态和激发态能级位置。 结果表明,2种染料的能级位置符合染料敏化太阳能电池的要求。 将它们用作染料敏化太阳能电池中的光敏化剂,在AM1.5-100×10-3 W/cm2的光强下,MXD8敏化电池的开路电压(VOC)为614 mV,短路电流密度(JSC)为5.76×10-3 A/cm2,填充因子(FF)为0.66,总光电转换效率为2.33%。 尽管MXD9引入3,4乙撑二氧噻吩作为共轭桥,其光电转换效率却较MXD8低（1.27%）。 阻抗测试表明,MXD9光电转换效率较低的原因主要是电子更容易复合。 该结果表明,电子复合可能与分子共轭体系增大导致极化率增加有关。     

染料敏化太阳能电池中meso-D-π-A卟啉分子设计的最新研究进展

与已经商业化的硅太阳能电池相比,染料敏化太阳能电池(Dye-sensitized solar cells, DSC)因制备工艺简单、成本低和较高的光电转换效率而成为研究的热点。本文从设计D-π-A卟啉染料的思路出发,阐述了DSC中meso-卟啉染料的给体、取代基、π桥及受体对其性能的影响。     

茚苯胺青色染料光退色的研究

本文研究了一系列茚苯胺青影像染料的光退色动力学和光退色机理。实验结果表明,这些染料在醋酸丁酯溶液中的光退色符合一级反应动力学。茚苯胺染料光退色过程中存在光氧化反应。用改进的PPP-CI方法计算染料分子的跃迁能和电荷密度,结果表明,茚苯胺染料的光退色速率与染料分子中某些原子上的电荷密度有关,单重态氧可能在光退色过程中起着重要作用。     

Acceptor tuning effect on TPA-based organic efficient sensitizers for optoelectronic applications—quantum chemical investigation

Structural Chemistry - A new series of triphenylamine (TPA)-based organic dyes (A1-A4) are characterized and implemented as photosensitizers for dye-sensitized solar cells (DSSCs). In the...     

Redox couple related influences of bulky electron donor as well as spacer in organic dye-sensitized mesoscopic solar cells

For dye-sensitized solar cells (DSCs), it is of great significance to understand the structure–performance relationship of photosensitizers. Herein, we scrutinize the influences of the arylamine electron donors as well as the fused thiophene spacer on the optoelectronic features of thin-film DSCs employing the tris(1,10-phenanthroline)cobalt(II/III) or the iodide/triiodide redox couple. Interestingly, the incorporation of bulky dihexyloxybenzene-substituted triphenylamine (DHOB-TPA) electron donor does not resulted in an improved electron lifetime, which is sharp contrast with the conventional concept on bulky electron donor. On the other hand, the introduction of the DHOB-TPA electron donor or the dithienopyrrole spacer significantly increases the molar absorption coefficients of dyes, which govern the performance of thin-film DSCs. This work demonstrates how organic dyes must be tailored carefully depending on the electrolyte red/ox couple used.     

Molecular design of organic dyes based on vinylene hexylthiophene bridge for dye-sensitized solar cells

Three donor-(π-spacer)-acceptor (D-π-A) organic dyes, containing different groups (triphenylamine, di(p-tolyl)phenylamine, and 9-octylcarbazole moieties) as electron donors, were designed and synthesized. Nanocrystalline TiO₂ dye-sensitized solar cells were fabricated by using these dyes. It was found that the variation of electron donors in the D-π-A dyes played an important role in modifying and tuning photophysical properties of organic dyes. Under standard global AM 1.5 solar condition, the DSSC based on the dye D2 showed the best photovoltaic performance: a short-circuit photocurrent density (J _sc ) of 13.93 mA/cm², an open-circuit photovoltage (V _oc ) of 0.71 V, and a fill factor (FF) of 0.679, corresponding to solar-to-electric power conversion efficiency (η) of 6.72%. Supported by the Key Project of Hunan Province of China (Grant No. 2008FJ2004), Natural Science Foundation of Hunan Province of China (Grant Nos. 09JJ3020 & 09JJ4005), and Scientific Research Fund of Hunan Provincial Education Department (Grant No. 08C888).     

New D-π-A dyes for efficient dye-sensitized solar cells

Functional organic dyes have promising prospect in dye-sensitized solar cells as a crucial element, of which sensitizers based on donor-π-acceptor are the most important dyes. On the basis of the structures of the aromatic amine donors such as triphenylamine and indoline, this paper reviews the photoelectric conversion properties of organic sensitizers since 2008, and highlights research work in our laboratory in this area.     

分子整流的实验与理论研究进展*

分子电子器件的思想始于20世纪70年代,分子整流的研究在30多年中取得了显著进展,包括分子结构设计、实验测量以及理论模拟。本文简述了分子整流的发展历程,介绍了被广泛研究的分子整流体系以及分子水平整流机理,包括D-σ-A型、D-π-A型、D-A型、构象转变和界面引起的整流,以及负微分电阻现象。最后提出了分子整流研究中存在的一些问题,并展望了分子整流的研究和发展方向。     

Macrocyclic triphenylamine based organic dyes for efficient dye-sensitized solar cells

A novel class of organic D-π-A dyes employing macrocyclic triphenylamine dimer as electron donor was designed and synthesized for dye-sensitized solar cells. The prepared compounds showed high chemical and elelctrochemical stabilities as well as good long-wave absorption. Photovoltaic devices based on these dyes showed high open circuit voltage (higher than that of N3) and achieved a solar energy to electricity conversion efficiency of 6.31%. All the performances indicate the dyes containing macrocyclic triphenylamine dimer is a good candidate for dyes sensitized solar cells.     

Tuning the Electrical and Optical Properties of Diketopyrrolopyrrole Complexes for Panchromatic Dye‐Sensitized Solar Cells

A series of metal‐free organic dyes that were bridged by a diketopyrrolopyrrole moiety and were composed of indoline and triphenylamine as donor groups and furan and benzene as conjugated spacer groups were designed and synthesized for use in dye‐sensitized solar cells (DSCs). The photophysical properties, electrochemical properties, and performance of the DSCs were related to the structure of their corresponding dyes. Their absorption spectra broadened upon the introduction of the indoline and heterocyclic furan moieties through fine‐tuning of their molecular configuration. The overall conversion efficiencies of DSCs that were based on these dyes ranged from 5.14–6.53 %. Among the four dyes that were tested, indoline‐based ID01 and ID02 showed higher efficiencies (6.35 % and 6.53 %) as a result of their improved light‐harvesting efficiency and larger electron driving force. The ID01 dye, which contained an indoline moiety as an electron donor and a furan group as a π‐conjugated linker, showed an excellent monochromatic incident‐photon‐to‐current‐conversion efficiency (IPCE) spectrum (350–650 nm) with a maximum value of 78 % in the high plateau region and an onset value close to 800 nm. Intensity‐modulated photovoltage spectroscopy (IMVS) and impedance spectroscopy (IS) revealed that dyes that contained benzene conjugation spacers suppressed the charge‐recombination rate more efficiently than dyes that contained furan spacers, thereby resulting in improved photovoltage.     

Synthesis and Modeling of Acridine Dyes as Potential Photosensitizers for Dye‐Sensitized Photovoltaic Applications †

We have synthesized novel aromatic amine‐substituted acridine dyes as potential candidates for the photosensitizers in dye sensitized nanocrystalline semiconductor based solar cells (DSSC) cells. The protonation and quaternization of the acridine nitrogen led to acridine dyes with extended absorption from 400–800 nm. Computational modeling was used to evaluate a variety of structures to achieve insights for correlating these types of molecular structures with predicted absorption spectra. Pertinent dihedral angles as well as bond lengths were evaluated to assess and compare planarity and conjugation for these dyes. Other predictions include plots of the HOMO and LUMO levels to qualitatively examine electron distributions and the potential for electron injection. The results from modeling along with the experimental data consisting of synthesis, characterization and UV‐visible absorption properties of the selected dyes are presented.     

Electron-rich heteroaromatic conjugated polypyridine ruthenium sensitizers for dye-sensitized solar cells

Ru(II) heteroleptic complexes as photosensitizers for dye-sensitized solar cells (DSCs) are presented. The article outlines design strategies, synthetic routes, optical and photovoltaic properties of ruthenium dyes based on polypyridines as ancillary ligands containing π-conjugated electron-rich heteroaromatic groups. The integration of donor heteroaromatic substituents, typically thiophene-based moieties, strongly improves the optical properties of the sensitizers in terms of bathochromic and hyperchromic shift compared to prototypical dyes N3 and N719. These favorable properties in turn yield DSCs with superior light harvesting abilities, higher external quantum efficiencies, improved device photocurrents, and top-ranked power conversion efficiencies. In combination with excellent stabilities under thermal stress and light soaking, this class of DSC photosensitizer has great potential for practical applications.