具有推拉电子结构卟啉染料的合成及其在染料敏化太阳能电池中的应用

将N,N’-二-(9,9’-二己基芴)胺作为电子供体引入具有推拉电子结构的卟啉染料中,设计合成了2个新的染料敏化太阳能电池(DSSCs)敏化剂WP-1和WP-2。利用核磁共振氢谱和高分辨质谱对染料结构进行了表征。测试了染料的紫外-可见吸收光谱。将其应用于染料敏化太阳能电池中,在模拟太阳光(100×10-3W/cm2)照射下,染料WP-1和WP-2敏化电池的能量转换效率分别达到了4.01%和7.07%。WP-2敏化的电池封装后经自然光照射500 h后,光电效率仍能维持在初始效率的98%以上。说明N,N’-二-(9,9’-二己基芴)胺作为电子供体,很适合推拉电子结构的卟啉染料。不仅丰富了用于卟啉染料的电子供体的种类,也为进一步将二芴胺衍生物引入到卟啉染料中的研究奠定了基础。     

有序宏孔-介孔TiO_2薄膜的制备及其在染料敏化太阳能电池中的应用

我们使用表面活性剂P123和聚苯乙烯球双模板技术,合成了多级有序的宏孔/介孔TiO2薄膜,并将其与P25多孔薄膜复合形成双层结构的染料敏化太阳能电池光阳极.实验结果表明,宏孔/介孔TiO2薄膜层的引入,有效地提高了光阳极对太阳光的散射以及捕获能力,从而提高了染料敏化太阳能电池的光电转化效率.与使用单一P25光阳极的染料敏化太阳能电池相比,双层TiO2结构的染料敏化太阳能电池所产生的短路光电流密度从7.49上升到了10.65mA/cm2,开路电压也从0.65提高到了0.70V.在太阳光强度为AM1.5时所测得的光电转化效率表明,双层TiO2结构的染料敏化太阳能电池的光电转化效率为5.55%,比单层P25结构的染料敏化太阳能电池的光电转化效率提升了83%.     

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。     

基于p型光电极的染料敏化太阳能电池研究进展

基于p型光电极的染料敏化太阳能电池是一种受到广泛关注的新型太阳能电池。根据电池的结构不同可以将其分为p型和p-n叠层型染料敏化太阳能电池。其中p-n型叠层染料敏化太阳能电池的理论光电效率可以达到43%,高于传统的基于n型TiO_2光阳极的染料敏化太阳能电池理论效率(30%),引起了科学界的高度关注。本文将总结基于p型光电极染料敏化太阳能电池(p型和p-n型叠层器件)的研究成果,重点介绍用于p型和p-n型叠层染料敏化太阳能电池的电极材料,染料及电解质的研究进展;同时总结目前该类电池发展中亟需解决的问题以及进一步提高器件效率的途径。     

大面积全柔性染料敏化太阳能电池光电性能优化

设计并制作了大面积高效全柔性染料敏化太阳能电池（DSCs）.通过引入光散射层或施加机械压力,DSCs的光电转化效率有了大幅度提高.实验室小面积（0.4 cm×0.4 cm）柔性DSCs的光电转化效率达到5.50%.大面积（2 cm×3 cm,活性面积为2.7 cm²）DSCs的光电转化效率从未进行处理的1.52%上升到1.81%和2.50%,分别提高了20.0%和66.7%.5 cm×7 cm面积的DSCs（活性面积为16.2 cm²）的光是转化效率在未做任何优化处理的条件下达到了1.60%(光强40 mW·cm^-2).同时,本文对提高光电转化效率的机理进行了深入研究.电化学阻抗测试结果表明,加压法能明显减小电池的内部串联电阻（R_s）及TiO₂/染料/电解液界面间的传荷电阻(R_ct).扫描电镜结果也显示加压后TiO₂粒子之间粘结更加紧密,更利于电子在TiO₂薄膜中的传输及染料的吸附.另外,900 h的长期稳定性实验结果表明,制作的柔性DSCs的各项光电性能参数均无明显下降.该实验结果为柔性染料敏化太阳能电池的基础研究和大面积产业化技术研究奠定了基础.     

准固态染料敏化太阳能电池中电解质体系的研究进展

染料敏化太阳能电池(Dye Sensitized Solar Cells)是新一代将光能转化为电能的重要能源转换装置。它具有低廉的材料和器件制作成本、较高的光电转换效率以及电池制作过程简单等诸多优点,拥有广阔的应用空间和巨大的潜在商业价值,因而吸引了广泛的研究关注。染料敏化太阳能电池主要由染料敏化的光阳极、电解质和对电极三个部分组成。其中,电解质作为染料敏化太阳能电池的重要组成部分,其对离子的传导和扩散,以及促进染料再生的能力极大地影响着染料敏化太阳能电池的电荷传输和光电性能。本文聚焦于染料敏化太阳能电池准固态电解质体系,主要从聚合物凝胶电解质、有机小分子凝胶电解质和无机纳米粒子凝胶电解质三大方面综述讨论了该研究领域当前最新研究进展,并对其未来研究趋势进行了展望。     

新型甲基吲哚季铵盐的制备及其光电性能研究

以2,3,3-三甲基吲哚为原料,合成了5种甲基吲哚阳离子季铵盐,通过核磁共振氢谱、质谱等手段,对合成的化合物进行了结构表征,并将其作为有机电解质应用于染料敏化太阳能电池,测定了其相应的光电转换效率,探讨了阳离子季铵盐化合物结构与光电性能的关系.     

聚乙烯醇缩醛基准固态电解质及其在染料敏化太阳能电池中的应用

采用聚乙烯醇缩甲醛(PVF)与聚乙烯醇缩丁醛(PVB)2种聚乙烯醇缩醛类聚合物制作了准固态电解质并应用在了染料敏化太阳能电池上.利用红外光谱,热力学及电化学的方法对聚合物及聚合物电解质进行了表征,结果表明聚合物中C O及O—C—O基团可以通过氧原子与锂离子相互作用促进Li I的电离.PVB中丙基侧链对其热力学及电化学性能有显著的影响.通过对电解质组成进行优化,PVF和PVB基电解质的电导率分别达到2.5 m S·cm~(-1)及4.2 m S·cm~(-1),极限扩散电流分别为10.05 m A·cm-2(扩散系数为1.84×10-6cm2·s~(-1))和17.89 m A·cm-2(扩散系数为3.23×10-6cm2·s~(-1)).PVF及PVB基准固态染料敏化太阳能电池分别达到了4.18%和6.06%的光电转化效率,并展现了良好的稳定性.     

基于p型光电极的染料敏化太阳能电池研究进展

基于p型光电极的染料敏化太阳能电池是一种受到广泛关注的新型太阳能电池。根据电池的结构不同可以将其分为p型和p-n叠层型染料敏化太阳能电池。其中p-n型叠层染料敏化太阳能电池的理论光电效率可以达到43%,高于传统的基于n型TiO₂光阳极的染料敏化太阳能电池理论效率（30%）,引起了科学界的高度关注。本文将总结基于p型光电极染料敏化太阳能电池（p型和p-n型叠层器件）的研究成果,重点介绍用于p型和p-n型叠层染料敏化太阳能电池的电极材料,染料及电解质的研究进展;同时总结目前该类电池发展中亟需解决的问题以及进一步提高器件效率的途径。     

基于不同取代基的噻吩-三苯胺染料敏化剂的合成与光伏性能

本文合成了含3种不同取代基的噻吩-三苯胺染料敏化剂(H1,H2和H3),并将其应用于二氧化钛纳米晶染料敏化太阳能电池.系统地研究了3种染料的光物理、电化学和光伏性能.基于H1的染料敏化太阳能电池获得了9.10%的光电转换效率(Voc=0.72V,Jsc=18.03mAcm-2,FF=0.70).     

Oligothiophene-containing coumarin dyes for efficient dye-sensitized solar cells

We have developed oligothiophene-containing coumarin dyes fully functionalized for dye-sensitized nanocrystalline TiO(2) solar cells (DSSCs). DSSCs based on the dyes gave good performance in terms of incident photon-to-current conversion efficiency (IPCE) in the range of 400-800 nm. A solar energy-to-electricity conversion efficiency (eta) of 7.4% was obtained with a DSSC based on 2-cyano-3-[5'-(1,1,6,6-tetramethyl-10-oxo-2,3,5,6-tetrahydro-1H,4H,10H-11-oxa-3a-aza-benzo[de]anthracen-9-yl)-[2,2']bithiophenyl-5-yl]acrylic acid (NKX-2677) under simulated AM 1.5G irradiation (100 mW cm(-2)) with a mask: short-circuit current density (J(sc)) = 13.5 mA cm(-2); open-circuit voltage (V(oc)) = 0.71 V; fill factor (FF) = 0.77. Transient absorption spectroscopy measurements indicated that electron injection from NKX-2677 to the conduction band of TiO(2) is very rapid (<100 fs), which is much faster than the emission lifetime of the dye (1.0 ns), giving a highly efficient electron injection yield of near unity.     

Influence of surface-attachment functionality on the aggregation, persistence, and electron-transfer reactivity of chalcogenorhodamine dyes on TiO2

Chalcogenorhodamine dyes bearing phosphonic acids and carboxylic acids were compared as sensitizers of nanocrystalline TiO(2) in dye-sensitized solar cells (DSSCs). The dyes were constructed around a 3,6-bis(dimethylamino)chalcogenoxanthylium core and varied in the 9 substituent: 5-carboxythien-2-yl in dyes 1-E (E = O, Se), 4-carboxyphenyl in dyes 2-E (E = O, S), 5-phosphonothien-2-yl in dyes 3-E (E = O, Se), and 4-phosphonophenyl in dyes 4-E (E = O, Se). All dyes adsorbed to TiO(2) as mixtures of H aggregates and monomers, which exhibited broadened absorption spectra relative to those of purely amorphous monolayers. Surface coverages of dyes and the extent of H aggregation varied minimally with the surface-attachment functionality, the structure of the 9-aryl group, and the identity of the chalcogen heteroatom. Carboxylic acid-functionalized dyes 1-E and 2-E desorbed rapidly and completely from TiO(2) into acidified CH(3)CN, but phosphonic acid-functionalized dyes 3-E and 4-E persisted on TiO(2) for days. Short-circuit photocurrent action spectra of DSSCs corresponded closely to the absorptance spectra of dye-functionalized films; thus, H aggregation did not decrease the electron-injection yield or charge-collection efficiency. Maximum monochromatic incident photon-to-current efficiencies (IPCEs) of DSSCs ranged from 53 to 95% and were slightly higher for carboxylic acid-functionalized dyes 1-E and 2-E. Power-conversion efficiencies of DSSCs under white-light illumination were low (<1%), suggesting that dye regeneration was inefficient at high light intensities. The photoelectrochemical performance (under monochromatic or white-light illumination) of 1-E and 2-E decayed significantly within 20-80 min of the assembly of DSSCs, primarily because of the desorption of the dyes. In contrast, the performance of phosphonic acid-functionalized dyes remained stable or improved slightly on similar timescales. Thus, replacing carboxylic acids with phosphonic acids increased the inertness of chalcogenorhodamine-TiO(2) interfaces without greatly impacting the aggregation of dyes or the interfacial electron-transfer reactivity.     

Alkyl-functionalized organic dyes for efficient molecular photovoltaics

We designed and synthesized new alkyl-functionalized organic dyes, MK-1 and MK-2, for dye-sensitized solar cells (DSSCs). Based on the MK-2 dye, a high performance of efficiency (eta, 7.7%; short-circuit current density Jsc = 14.0 mA cm-2, open-circuit voltage Voc = 0.74 V, and fill factor FF = 0.74) was achieved under AM 1.5 G irradiation (100 mW cm-2). Remarkably, the relatively higher Voc for DSSCs based on MK-1 and MK-2 dyes, which have long alkyl chains, were observed among the organic dyes caused by the increasing of the electron lifetime in the conduction band of TiO2. Our molecular design of alkyl-functionalized dyes strongly suggests the promising performance of molecular photovoltaics based on organic dyes.     

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.     

Ethoxy‐substituted Oligo‐phenylenevinylene‐Bridged Organic Dyes for Efficient Dye‐Sensitized Solar Cells

Organic dyes with ethoxy‐substituted oligo‐phenylenevinylene as chromophores were synthesized for dye‐sensitized solar cells (DSSCs), and the detailed relationships between the dye structures, photophysical properties, electrochemical properties, and performances of DSSCs were described. The dye S3O showed broad IPCE spectra in the spectral range of 350–750 nm, and the dye S1P showed solar energy‐to‐electricity conversion efficiency (() of up to 4.23% under AM 1.5 irradiation (100 mW/cm²) in comparison with the reference Ru‐complex (N719 dye) with an η value of 5.90% under similar experimental conditions.     

High‐Performance Dipolar Organic Dyes with an Electron‐Deficient Diphenylquinoxaline Moiety in the π‐Conjugation Framework for Dye‐Sensitized Solar Cells

We report here the synthesis and electrochemical and photophysical properties of a series of easily prepared dipolar organic dyes and their application in dye‐sensitized solar cells (DSSCs). For the six organic dyes, the molecular structures comprised a triphenylamine group as an electron donor, a cyanoacrylic acid as an electron acceptor, and an electron‐deficient diphenylquinoxaline moiety integrated in the π‐conjugated spacer between the electron donor and acceptor moieties. The incorporation of the electron‐deficient diphenylquinoxaline moiety effectively reduces the energy gap of the dyes and broadly extends the spectral coverage. DSSCs based on dye 6 produced the best overall cell performance of 7.35 %, which translates to approximately 79 % of the intrinsic efficiency of the DSSCs based on the standard N719 dye under identical experimental conditions. The high performance of DSSCs based on dye 6 among the six dyes explored is attributed to the combined effects of high dye loading on a TiO₂ surface, rapid dye regeneration, and effective retardation of charge recombination.     

Enhanced performance of the dye-sensitized solar cells with phenothiazine-based dyes containing double D-A branches

Double donor-acceptor (D-A) branched dyes (DBD) with a phenothiazine unit as electron donor and a 2-cyanoacrylic acid unit as electron acceptor were synthesized and used as sensitizers for solar cells (DSSCs). The conversion efficiency of the DSSCs amounts up to 4.22% (2.91% for the single D-A branched dye) under AM 1.5 G irradiation. The results show that the performance of DSSCs can be effectively enhanced by the cooperation of two donor-acceptor containing branches in one molecule of the dyes.     

High-Performance Dipolar Organic Dyes with an Electron-Deficient Diphenylquinoxaline Moiety in the π-Conjugation Framework for Dye-Sensitized Solar Cells

We report here the synthesis and electrochemical and photophysical properties of a series of easily prepared dipolar organic dyes and their application in dye-sensitized solar cells (DSSCs). For the six organic dyes, the molecular structures comprised a triphenylamine group as an electron donor, a cyanoacrylic acid as an electron acceptor, and an electron-deficient diphenylquinoxaline moiety integrated in the π-conjugated spacer between the electron donor and acceptor moieties. The incorporation of the electron-deficient diphenylquinoxaline moiety effectively reduces the energy gap of the dyes and broadly extends the spectral coverage. DSSCs based on dye 6 produced the best overall cell performance of 7.35?%, which translates to approximately 79?% of the intrinsic efficiency of the DSSCs based on the standard N719 dye under identical experimental conditions. The high performance of DSSCs based on dye 6 among the six dyes explored is attributed to the combined effects of high dye loading on a TiO(2) surface, rapid dye regeneration, and effective retardation of charge recombination.     

Electronic optimization of heteroleptic Ru(II) bipyridine complexes by remote substituents: synthesis, characterization, and application to dye-sensitized solar cells

We prepared a series of new heteroleptic ruthenium(II) complexes, Ru(NCS)(2)LL' (3a-3e), where L is 4,4'-di(hydroxycarbonyl)-2,2'-bipyridine and L' is 4,4'-di(p-X-phenyl)-2,2'-pyridine (X = CN (a), F (b), H (c), OMe (d), and NMe(2) (e)), in an attempt to explore the structure-activity relationships in their photophysical and electrochemical behavior and in their performance in dye-sensitized solar cells (DSSCs). When substituent X is changed from electron-donating NMe(2) to electron-withdrawing CN, the absorption and emission maxima reveal systematic bathochromic shifts. The redox potentials of these dyes are also significantly influenced by X. The electronic properties of the dyes were theoretically analyzed using density functional theory calculations; the results show good correlations with the experimental results. The solar-cell performance of DSSCs based on dye-grafted nanocrystalline TiO(2) using 3a-3e and standard N3 (bis[(4,4'-carboxy-2,2'-bipyridine)(thiocyanato)]ruthenium(II)) were compared, revealing substantial dependences on the dye structures, particularly on the remote substituent X. The 3d-based device showed the best performance: η = 8.30%, J(SC) = 16.0 mA·cm(-2), V(OC) = 717 mV, and ff = 0.72. These values are better than N3-based device.     

High‐Performance Dye‐Sensitized Solar Cells Based on Phenothiazine Dyes Containing Double Anchors and Thiophene Spacers

A series of new push–pull phenothiazine‐based dyes ( HL1 , HL2 , HL3 , HL4 ) featuring various π spacers (thiophene, 3‐hexylthiophene, 4‐hexyl‐2,2′‐bithiophene) and double acceptors/anchors have been synthesized, characterized, and used as sensitizers for dye‐sensitized solar cells (DSSCs). Among them, the best conversion efficiency (7.31 %) reaches approximately 99 % of the N719‐based (7.38 %) DSSCs fabricated and measured under similar conditions. The dyes with two anchors have more efficient interfacial charge generation and transport compared with their congeners with only single anchor. Incorporation of hexyl chains into the π‐conjugated spacer of these double‐anchoring dyes can efficiently suppress dye aggregation and reduce charge recombination.