一种含氧供电基团的染料合成及其光伏性能

以对溴苯酚为原料,经碘丁烷的烷基化后,与硼酸三甲酯反应生成对丁氧基苯硼酸.环戊二噻吩经N-溴代丁二酰亚胺(NBS)的溴化和Vilsmeier-Haack反应,再与对丁氧基苯硼酸偶联、氰基乙酸缩合,生成目标化合物环戊二噻吩基光敏染料(L1).该化合物是一种以含氧基团为给体,环戊二噻吩作为共轭桥的有机染料,将其制备成有机染料敏化太阳能电池,在AM 1.5,100 mW/cm2的光强下,电池的单色光的光电转换效率(IPCE)值达到62%,开路电压(Voc)为535mV,短路电流密度(Jsc)为6.4mA·cm-2,填充因子(FF)为0.60,总光电转换效率为2.1%.     

掺P25水热法制备纳晶多孔TiO2薄膜电极

以水热法为基础,向其溶胶中掺入适量的P25(二氧化钛粉体),来制备纳晶TiO₂胶体,以纳晶TiO₂为电子传输体组装染料敏化太阳能电池.通过XRD、SEM、UV-vis和电池的光电性能测试,来分析掺入P25对染料敏化太阳能电池性能的影响.结果表明,加入适量P25([P25]/[Ti]=0.2)后,染料敏化太阳能电池性能达到最佳值,在100 mW/cm²光照条件下,光电转换效率达到5.4%.     

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.     

有机染料敏化网状二氧化钛纳米纤维微孔膜太阳能电池研究

利用静电纺丝技术, 在TiO₂纳米粒子上电纺一层网状TiO₂纳米纤维微孔膜作为光散射层, 并在TiO₂纳米粒子中掺杂少量MgO以抑制电子和空穴的复合, 得到TiO₂纳米纤维/纳米粒子复合光阳极用于染料敏化太阳能电池. 将这种光阳极分别与有机三苯胺染料SD2, SD3或钌染料N719及鹅脱氧胆酸(CDCA)共敏化时, 在AM 1.5 (100 mW/cm²)的模拟太阳光照射下, 染料敏化太阳能电池的光电转换效率达到6.35%～8.85%. 同时, 使用半固态电解质可以达到液态电解质90%的光电转换效率.     

半菁类染料敏化太阳能电池的光电化学性能研究

研究了三种不同长度碳链取代的半菁类染料2-[4-(N,N-二羧乙基)氨基]苯乙烯基-1,3,3-三甲基苯并吲哚鎓碘(BIDC1)、2-[4-(N,N-二羧乙基)氨基]苯乙烯基-1-丁基-3,3-二甲基苯并吲哚鎓碘(BIDC2)和2-[4-(N,N-二羧乙基)氨基]苯乙烯基-1-辛基-3,3-二甲基苯并吲哚鎓碘(BIDC3)敏化太阳能电池的光电化学性能。其中BIDC1的敏化效果最好,在100mW/cm2氙灯光源下,开路电压、短路电流、填充因子和转换效率分别是430mV、1.31mA/cm2、0.52、0.29%。研究表明,随着半菁染料碳链取代基的增长,光电转换效率逐渐降低。     

以苯并噻二唑为辅助受体的N-苯基咔唑类染料敏化剂的合成及光伏性能

以N-苯基咔唑为电子给体,苯并噻二唑为辅助电子受体,噻吩或苯为π桥,氰乙酸或罗丹宁乙酸为键合受体,设计合成了四个N-苯基咔唑类染料敏化剂.对所合成的染料敏化剂的光谱性能和光电转换性能进行了研究.以氰乙酸为受体的染料敏化剂尽管最大吸收波长和摩尔吸光系数较以罗丹宁乙酸为受体的染料敏化剂低,但由于其电子注入效率高,导致其光电流和光电压均较优.以苯环为桥键的染料敏化剂较以噻吩环为桥键的染料敏化剂具有更好的光电流和光电压,因此四种染料敏化剂中,以苯基作为桥键,氰基乙酸作为受体的染料敏化剂获得较佳的光电转换效率5.28%(J_(SC)=9.14 mA/cm~2,V_(OC)=0.74 V,FF=0.78).     

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。     

吸电子基团修饰的三联噻吩及其对纳晶TiO2电极的敏化

设计合成了吸电子基团(2氰-基-2-羧基乙烯基)修饰的三联噻吩3T-CCV,研究了它的光物理和光电化学性质.密度泛函计算证明,3T-CCV受光激发可有效地发生分子内电荷分离.研究表明,在模拟太阳光AM1.5(70 mW/cm²)照射下,以3T-CCV作为光敏剂的纳晶TiO₂太阳电池的光电转换效率达到3.25%.     

高相转变温度的离子凝胶电解质基准固态染料敏化太阳电池

染料敏化太阳电池(DSC)以其低价、高效等优势, 成为学术界和工业界的研究热点. 传统液态电解质由于易挥发、易泄漏等问题, 导致基于液态电解质的电池难以保持长期稳定, 影响光伏技术的应用. 本文合成了N,N'-1,5-戊二基双月桂酰胺, 将其作为有机小分子胶凝剂(LMOG)胶凝离子液体电解质(ILE)制备了离子凝胶电解质(IGE)并组装成准固态电池(QS-DSCs). 差示扫描量热测试显示该凝胶电解质的相转变温度(T_gel)为104.7℃, 具有良好的本征热稳定性.利用循环伏安法、电化学阻抗谱、调制光电压/光电流谱分别研究了液态电池和准固态电池内部电子传输和复合动力学过程. 结果表明, 凝胶电解质的三维网络结构加速了TiO₂光阳极/电解质界面电子与电解质中I₃^-的复合过程, 使电子寿命降低, 导致准固态电池的光电转换效率略低于液态电池. 在AM1.5 (100 mW·cm^-2)及50℃条件下的加速老化测试结果显示, 持续老化1000 h后其光电转换效率(η)无衰减,而液态电池的光电转换效率衰减为初始值的86%, 表明准固态电池具有良好的光热稳定性.     

TiO2/SnO2复合空心球在染料敏化太阳能电池中的应用

采用模板辅助法制备了SnO2/TiO2复合空心球,样品直径为1.5~4.0μm,比表面积达到了92.9 m^2·g^-1,复合空心球表现出优越的光散射性能.以这种复合空心球作为染料敏化太阳能电池的光阳极,电池的光电转换效率可达到7.72%,高于SnO2微米球(2.70%)和TiO2微米球(6.26%).此外,以锐钛矿型TiO2纳米晶作为底层,SnO2/TiO2复合空心球作为光散射层制备的双层结构光阳极,电池光电转换效率进一步提升至8.43%.     

Organic dye bearing asymmetric double donor-π-acceptor chains for dye-sensitized solar cells

A novel efficient metal free sensitizer containing asymmetric double donor-π-acceptor chains (DC) was synthesized for dye-sensitized solar cells (DSSCs). Comparing to 3.80%, 4.40% and 4.64% for the DSSCs based on the dyes with single chain (SC1, SC2) and cosensitizers (SC1 + SC2), the overall conversion efficiency reaches 6.06% for DC-sensitized solar cells as a result of its longer electron lifetime and higher incident monochromatic photon-to-current conversion efficiency.     

Functionalized organic dyes containing a phenanthroimidazole donor for dye-sensitized solar cell applications

Five functionalized organic dyes (H6-10) containing a phenanthroimidazole unit as an electron donor were synthesized and characterized for use in dye-sensitized solar cell (DSSC) applications. Under standard global AM 1.5 solar conditions, the DSSCs based on dye H6 displayed the best performance, with an incident photon-to-current conversion efficiency (IPCE) exceeding 70% at wavelengths of 400–530 nm, a short-circuit photocurrent density of 10.98 mA cm^?2, an open-circuit voltage of 0.68 V, a fill factor of 0.69, and an overall conversion efficiency of 5.12%. This efficiency is ～94% of that for JK2 cells (5.46%) and ～72% of that for N719 cells (7.07%) under the same conditions.     

Transition metal complexes on mesoporous silica nanoparticles as highly efficient catalysts for epoxidation of styrene

We have synthesized a series of catalysts for epoxidation of styrene by immobilizing salicylaldimine transition metal (copper, manganese, and cobalt) complexes on mesoporous silica nanoparticles (MSNs) with diameters of 120-150 nm. The prepared catalysts are characterized by infrared (IR) spectra, thermal gravimetric analyses (TGA), inductively coupled plasma (ICP), CHN elemental analysis, nitrogen adsorption-desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). These catalysts possess excellent catalytic efficiency in epoxidation of styrene when using tert-BuOOH (TBHP) as oxidant. Styrene shows a high conversion (～99%) as well as epoxide selectivity (～80%) over Cu-MSN catalysts, and high conversion (～99%) and moderate epoxide selectivity (～65%) over Mn-MSN and Co-MSN catalysts. The recycling experiment results indicate that these catalysts maintain catalytic activity even after being used for three cycles. Our results indicate that MSNs can serve as better catalyst supports.     

光引发常规乳液聚合制备氨基聚苯乙烯纳米粒子

采用一种简单易行的方法制备了氨基功能化的聚苯乙烯纳米粒子.首先,采用4-乙烯基苄氯与1,3-丙二胺置换反应制备了含有氨基功能基团的可聚合单体N-(3-氨基丙基)对乙烯基苄基亚胺(CVPD).然后,采用乳液聚合,以苯乙烯(St)和CVPD为共聚单体,水溶性的4-(2-羟乙氧基)苯基-(2-羟基-2-丙基)酮(Irgacure 2959)为光引发剂,十六烷基三甲基溴化铵(CTAB)为乳化剂,经紫外光辐照引发,合成了P(St-co-CVPD)二元共聚物的纳米胶乳.体系的乳化剂用量仅为体系总质量的0.1 wt%～0.8 wt%,远小于常用来制备纳米粒子的微乳液体系的乳化剂用量.用透射电子显微镜(TEM)和激光粒度分析仪(DLS)表征了P(St-co-CVPD)纳米粒子的粒径和粒径分布.用红外光谱(FTIR)和核磁共振(NMR)证明了P(St-co-CVPD)纳米粒子上氨基的存在,并通过茚三酮显色反应定量检测了氨基含量.分别研究了单体配比,引发剂浓度,乳化剂用量以及紫外光强度对反应体系的影响.实验结果表明,产物粒子尺寸为30～600 nm,氨基通过共价键连接在粒子上,其含量为1.2×10-5～1.6×10-4 mol/g.该乳液体系聚合反应速率较快,单体转化率在60 min内即可达到80%.所得粒子的氨基含量可以通过单体配比进行调节.粒子尺寸可通过单体配比,引发剂浓度,乳化剂用量以及紫外光强度进行调节.     

Enhanced conversion efficiency and surface hydrophobicity of nano-roughened Teflon-like film coated poly-crystalline Si solar cells

Nano-roughened Teflon-like film coated poly-crystalline Si photovoltaic solar cells (PVSCs) with enhanced surface hydrophobicity and conversion efficiency (η) are characterized and compared with those coated by a Si nanorod array or a standard SiN anti-reflection layer. The Teflon-like film coated PVSC surface reveals a water contact angle increasing from 89.3° to 96.2° as its thickness enlarges from 22 to 640 nm, which is much larger than those of the standard and Si nanorod array coated PVSC surfaces (with angles of 55.6° and 32.8°, respectively). After nano-roughened Teflon-like film passivation, the PVSC shows a comparable η(10.89%) with the standard SiN coated PVSC (η = 11.39%), while the short-circuit current (I(SC)) is slightly reduced by 2% owing to the slightly decreased UV transmittance and unchanged diode performance. In contrast, the Si nanorod array may offer an improved surface anti-reflection with surface reflectance decreasing from 30% to 5% at a cost of optical scattering and randomized deflection, which simultaneously decrease the optical transmittance from 15% to 3% in the visible region without improving hydrophobicity and conversion efficiency. The Si nanorod array covered PVSC with numerous surface dangling bonds induced by 1 min wet-etching, which greatly reduces the open-circuit voltage (V(OC)) by 10-15% and I(SC) by 30% due to the reduced shunt resistance from 3 to 0.24 k?. The nano-scale roughened Teflon-like film coated on PVSC has provided better hydrophobicity and conversion efficiency than the Si nanorod array covered PVSC, which exhibits superior water repellant performance and comparable conversion efficiency to be one alternative approach for self-cleaning PVSC applications.     

Triaryl linked donor acceptor dyads for high-performance dye-sensitized solar cells

The effect of changing substituents of organic dyes for their performance on dye-sensitized solar cells (DSSCs) is examined. These dyes consist of an aromatic amine donor group, a cyanoacrylic acid acceptor group, and a triaryl spacer group, while they are linked together by consecutive palladium catalyzed coupling reactions. These materials exhibit strong charge transfer absorption bands in the UV/vis region. Their redox potential levels were estimated by cyclic voltammetry, and found to suit well to the charge flow in DSSCs. Adding electron-donating substituents on the phenyl groups of aromatic amines increased the electron density on the donor groups, therefore reduced the HOMO/LUMO band gap. These dyes were chemisorbed on the surface of nanocrystalline TiO₂, and fabricated into DSSCs through standard operations. For a typical device the maximal monochromatic incident photon-to-current conversion efficiency (IPCE) can reach to 80%, with a short-circuit photocurrent density (J_sc) 16.34 mA cm⁻², an open-circuit photovoltage (V_oc) 0.68 V, and fill factor (FF) 0.55, which corresponds to an overall conversion efficiency of 6.05%.     

Compact layer influence on hysteresis effect in organic–inorganic hybrid perovskite solar cells

Organic–inorganic hybrid perovskite solar cells have attracted great attention due to their high power conversion efficiency and low cost. However, an anomalous hysteresis effect exists in the perovskite solar cells, especially with TiO₂ as the n-type electron extraction layer. In this communication, we prepare two kinds of TiO₂ compact layers using Atomic Layer Deposition (ALD) and Spin-Coating (SC) methods and compare their influences on the hysteresis effect. By efficiency comparison and AC impedance spectroscopy study, we find that the thickness and morphology of compact layer have a significant influence on the hysteresis effect. Compared to the SC approach, the ALD prepared compact layer is ultra-thin with uniform morphology and shows small interfacial capacitance and large recombination resistance, meaning reduced interfacial charge accumulation and accelerated electron transport, which would relieve the hysteresis effect.     

双枝芳醚树枝形聚合物构象研究

合成了外围只以一个芘基团修饰、核心为苯胺的双枝芳醚树枝形聚合物Py-[Gn]2-NPh (n＝1～2), 利用分子内电子转移和激基复合物的形成对其折叠构象和折叠程度进行了研究. 二氯甲烷溶液中选择性激发芘基团, 树枝形聚合物Py-[Gn]2-NPh分子内发生从苯胺到芘基团之间的电子转移, 观察到了分子内外围芘基团和核心苯胺基团之间形成激基复合物的发光, 为芳醚树枝形聚合物折叠构象的存在给出了直接实验观察. 二氯甲烷溶液中1～2代Py-[Gn]2-NPh分子内电子转移效率分别为0.87和0.81, 速率常数分别为2.3×108和1.5×108 s－1. 利用电子转移速率常数估算得到1～2代Py-[Gn]2-NPh分子内给、受体之间的距离分别为0.79和0.81 nm, 说明双枝芳醚树枝形聚合物与单枝结构类似, 其外围基团也可以折叠到达分子内部接近核心的位置.     

Flexible organic photovoltaic devices based on oligothiophene derivatives

For the purpose of developing flexible organic photovoltaic devices, we have fabricated two flexible devices using 5-formyl- 2,2′：5′,2″：5″,2′″-quaterthiophene （4T-CHO）, 5-formyl-2,2′：5′, 2″：5″,2′″：5′″,2″″-quinquethiophene （5T-CHO） and 3,4,9,10-perylenetertracarboxylic dianhydride （PTCDA）. The PET-ITO/4T-CHO/PTCDA/A1 device has an open circuit voltage （Voc） of 1.56 V, photoelectric conversion efficiency of 0.77%. The PET-ITO/5T-CHO/PTCDA/A1 device has a Voc of 1.70 V, photoelectric conversion efficiency of 0.84%. The two flexible devices have high Voc （1.56 and 1.70 V）. It is possible that intermolecular hydrogen bonding between -CHO group of nT-CHO and carboxylic dianhydride of PTCDA contributes to enhancing the efficiency by promoting interfacial electron transfer and eliminating the subconducting band trap sites.     

Dye-sensitized TiO2 solar cells using imidazolium-type ionic liquid crystal systems as effective electrolytes

A novel ionic liquid crystal (ILC) system (C(12)MImI/I(2)) with a smectic A phase used as an electrolyte for a dye-sensitized solar cell (DSSC) showed the higher short-circuit current density (J(SC)) and the higher light-to-electricity conversion efficiency than the system using the non-liquid crystalline ionic liquid (C(11)MImI/I(2)), due to the higher conductivity of ILC. To investigate charge transport properties of the electrolytes in detail, the exchange reaction-based diffusion coefficients (D(ex)) were evaluated. The larger D(ex) value of ILC supported that the higher conductivity of ILC is attributed to the enhancement of the exchange reaction between iodide species. As a result of formation of the two-dimensional electron conductive pathways organized by the localized I(3)- and I- at S(A) layers, the concentration of polyiodide species exemplified by I(m)- (m = 5, 7, ...) was higher in C(12)MImI/I(2). However, as the increment of the concentration of polyiodide species is less than that of D(ex), the contribution of a two-dimensional structure of the conductive pathway through the increase of collision frequency between iodide species was proposed. Furthermore, a quasi-solid-state ionic liquid crystal DSSC was successfully fabricated by employing a low molecular gelator. Addition of the 5.0 g/L gelator to ILC improved light-to-electricity conversion efficiency through the increase of J(SC) due to the enhancement of the conductivity in C(12)MImI/I(2)-gel.