菁染料薄膜的光谱性能及稳定性的研究

本文研究了６种长链菁染料薄膜的光谱特性与光稳定性，以及两种抗氧剂对其薄膜光稳定性的影响，研究表明，结构相近的菁染料利用旋涂法成膜后，光稳定性与其母核的结构有关，依吲哚〉喹啉〉恶唑〉塞唑〉硒唑而变，与溶液状态相类似，两种抗氧剂均为有效的单重态氧猝灭剂，都能提高菁染料的光稳定性。     

高分子染料的光稳定性研究

光稳定性是衡量高分子染料的一个重要指标,而高分子染料的光稳定性主要与高分子骨架结构、染料母体结构及着色工艺等因素有关.本文详细分析了高分子染料光褪色的原因及机理,并针对影响高分子染料光稳定性的各因素,提出相应的改进措施.     

双羟基七甲川菁染料的合成及其光谱性能研究

通过分子设计,分别以2,3,3-三甲基吲哚和1,1,2-三甲基-1H-苯并[e]吲哚为原料,首先合成两种季铵盐,再分别同2-氯-1-甲酰-3-羟基亚甲基环己烯缩合,利用Suzuki-Miyaura反应实现染料中位C—C偶联,以超过70%的收率制备了4种带有活性羟基的七甲川菁染料。利用核磁和高分辨率质谱对染料结构进行了表征。以乙醇为溶剂,用紫外-可见光谱仪考察了染料的光谱性能。采用电流为13.4 A的高压氙灯为光源,考察了染料的光稳定性。探究了pH对染料颜色的影响,并尝试推论变色机理。结果表明,4种七甲川菁染料均在近红外区产生较强吸收,在无水乙醇中均具有良好的光稳定性。不同pH下,染料的光谱性能研究发现,七甲川菁染料吸收光谱受pH影响较大,在pH=5～7时,染料在近红外区有最佳吸收。     

新型萘四酰亚胺类长波长荧光染料的构建及其光谱调控

本文通过杂环胺类对二溴萘四酰亚胺的亲核反应,分别设计合成了8个未见报道的基于萘四酰亚胺母体的新型单取代或者双取代荧光染料.系统性光谱研究表明,胺类的推电子作用差异可以很好地调控其吸收和荧光波长,使之成为一类性能良好的可见或长波长荧光染料(最大吸收509—580 nm;最大发射565—638 nm;荧光量子效率0.21—0.54;Stokes位移36—77 nm).     

分散红玉M—GFL染料晶型稳定性与染色性能的关系

本文对分散红玉Ｍ－ＧＦＬ（Ｃ．Ｉ．分散红７３）不同晶态的晶型稳定性,染料分散液的热稳定性与染色性能之间关系作了阐述。     

品红甲亚胺染料影像光稳定性的研究——抗氧化剂和单重态氧的反应能力及其对染料影像光褪色的影响

本文研究了苯酚类(A),双酚类(B),对苯二酚类(C),色满类(D)和双螺色满类(E)抗氧化剂的性能。通过循环伏安法测定了它们的氧化电位;用类似Stern-Volmer关系图求得各抗氧化剂和单重态氧的反应速率常数。抗氧化剂的氧化电位越小,和单重态氧的反应速率常数越大,对品红甲亚胺染料影像的防褪色效果越好,进一步证实了染料褪色的光氧化反应机理。在这些抗氧化剂中,它们的防褪色效果依次为D>E>C>B>A。     

一种新型AIE/AIEE特征荧光染料的合成与光谱性质研究

聚集诱导发光增强(AIEE)现象,因其特殊的荧光性质在已成为国内外研究的热点。本论文设计并合成了一种新型AIEE的荧光染料,首先以2-羟基-6-萘甲醛为骨架,在1号位引入醛基,其次,醛基在与1-氨基苯硫醇反应,合成新型聚集诱导发光增强AIEE荧光染料,经分离纯化后获得产物Np-COH。进一步对产物通过质谱确定其分子量为410.05,并对此荧光染料的紫外光谱和不同条件下的荧光光谱进行了测定。测定结果显示该新型荧光染料在水比二甲基亚砜为30%条件下,表现了较好的荧光性能,在水比二甲基亚砜大于50%条件下,荧光较弱。Np-COH荧光染料在515 nm处的荧光受p H值影响有微弱的变化,说明染料能在较宽的pH值范围内使用。     

合成纤维及其混纺织物用染料的研究(Ⅳ)偶氮型活性分散染料结构与性能的关系

本文合成了以对-(β-羟乙基砜硫酸酯)苯胺、2-氨基-6-(β-羟乙基砜硫酸酯)苯骈噻唑为重氮组分,以不同取代端氨基苯胺为偶合组分的2个系列偶氮型活性分散染料.探讨了这些染料的分子结构与其在涤-棉混纺织物上分配的关系;与染料吸收光谱的关系;与涤、棉两组分上颜色的关系及与染色织物耐晒牢度的关系.     

PSAF@淀粉无机-有机杂化絮凝剂的合成与表征

将粉煤灰与固体氢氧化钠混合焙烧活化,经酸浸、静置后引入淀粉和引发剂K2S2O8,通过水解、缩聚等步骤一步法合成聚硅酸铝铁(PSAF)-淀粉杂化絮凝剂,考察了淀粉添加量和引发剂用量对絮凝性能的影响.研究发现,当淀粉添加量为40%,引发剂用量为1%时,对低浊度模拟水样的浊度去除率最高可达76.3%.PSAF@淀粉杂化絮凝剂电导率随浓度呈现良好的线性关系,在1086 cm-1处保留更为明显的淀粉葡萄糖C-O-C伸缩振动吸收峰,半衰期温度也较PSAF-淀粉混合物要高,热稳定性更好,表明PSAF-淀粉杂化产物无机-有机间以共价键形式结合.     

缓冲层在有机太阳能电池中的应用

有机太阳能电池的有机活化层与阴、阳极接触界面的性质对器件性能起着重要的作用。本文综述了近年来有机太阳能电池中使用的阴、阳极界面缓冲材料的类型和工作机制。结果表明,阴、阳极缓冲层的界面修饰对太阳能电池的能量转换效率、寿命和稳定性具有决定性的影响。因此,缓冲层的特性研究对器件结构的改进和性能优化具有一定的指导意义。该研究为其它缓冲层材料在有机太阳能电池中的成功应用提供了有益的实验思路。     

N-Aryl stilbazolium dyes as sensitizers for solar cells

Eight new N-arylstilbazolium chromophores with electron donating -NR₂ (R = Me or Ph) substituents have been synthesized via Knoevenagel condensations and isolated as their PF₆⁻ salts. These compounds have been characterized by using various techniques including ¹H NMR and IR spectroscopies and electrospray mass spectrometry. UV-vis absorption spectra recorded in acetonitrile are dominated by intense, low energy π → π* intramolecular charge-transfer (ICT) bands, and replacing Me with Ph increases the ICT energies. Cyclic voltammetric studies show irreversible reduction processes, together with oxidation waves that are irreversible for R = Me, but reversible for R = Ph. Single crystal X-ray structures have been determined for three of the methyl ester-substituted stilbazolium salts and for the Cl⁻ salts of their picolinium precursors. Time-dependent density functional theory calculations afford reasonable predictions of ICT energies, but greater rigour is necessary for -NPh₂ derivatives. The four new acid-functionalized dyes give moderate sensitization efficiencies (ca. 0.2%) when using TiO₂-based photoanodes, with relatively higher values for R = Ph vs Me, while larger efficiencies (up to 0.8%) are achieved with ZnO substrates.     

Subtly adjusted active layer self‐assembly process for efficient organic solar cells

The phase separation degree of active layers plays a vital role in enhancing the power conversion efficiency of organic solar cells. Two post treatments were employed to optimize the phase separation degree of active layers by subtly adjusting the self‐assembly process for SMPV1:PC₇₁BM based active layers (SMPV1, 2,6‐bis[2,5‐bis(3‐octylrhodanine)‐(3,3‐dioctyl‐2,2':5,2''‐terthiophene)]‐4,8‐bis((5‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b']dithiophene; PC₇₁BM, [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester). In this work, a power conversion efficiency of 7.93% was obtained for devices with an as‐cast active layer, which is close to the highest values reported for SMPV1 based devices. The power conversion efficiency was further increased to 8.64% or 8.99% for active layers with thermal annealing or thermal annealing together with solvent vapor annealing, respectively. The enhanced performance is mainly attributed to more efficient photon harvesting and charge transport induced by the post annealing treatment of the active layers. The face‐on molecular orientation of SMPV1 is increased for active layers with post annealing treatment, which is beneficial for charge transport along directions perpendicular to the substrate. This work further confirms the positive effect of post annealing treatment on the performance improvement of organic solar cells. © 2019 Society of Chemical Industry     

Block copolymers as efficient cathode interlayer materials for organic solar cells

Emerging needs for the large-scale industrialization of organic solar cells require high performance cathode interlayers to facilitate the charge extraction from organic semiconductors. In addition to improving the efficiency, stability and processability issues are major challenges. Herein, we design block copolymers with well controlled chemical composition and molecular weight for cathode interlayer applications. The block copolymer coated cathodes display high optical transmittance and low work function. Conductivity studies reveal that the block copolymer thin film has abundant conductive channels and excellent longitudinal electron conductivity due to the interpenetrating networks formed by the polymer blocks. Applications of the cathode interlayers in organic solar cells provide higher power conversion efficiency and better stability compared to the most widely-applied ZnO counterparts. Furthermore, no post-treatment is needed which enables excellent processability of the block copolymer based cathode interlayer.     

A solar regenerable cathodic electron acceptor for microbial fuel cells

In this study, a high performance and solar regenerable cathodic electron acceptor, I₃⁻, was incorporated into a microbial fuel cell (MFC). Linear sweep voltammetry showed that a current density of 4.2 mA cm⁻² can be obtained from the electroreduction of I₃⁻. This value was approximately twice that of ferricyanide (Fe(CN)₆³⁻) and was independent of the pH of the electrolyte. The effect of regeneration conditions, such as the pH of the KI solution, KI concentration, oxygen flow rate and the Xe light intensity, on the I₃⁻ yield and performance of the MFC was investigated. A sufficient supply of I₃⁻ was achieved when the concentration of an air-saturated KI solution was greater than 0.2 M and its pH was around 2.0, under an irradiation higher than 300 mW cm⁻². Extended operation of the MFC showed that I₃⁻ is capable of supporting the MFC for long-term electricity generation. The maximum power output of the MFC using a catholyte containing 1.2 mM I₃⁻ + 0.2 M KI solution was 484.0 mW m⁻². This performance was greater than that (307.1 mW m⁻²) when using a catholyte containing 1.2 mM Fe(CN)₆³⁻ + 0.2 M KCl solution under the same conditions.     

用于敏化太阳能电池的二氧化钛光阳极材料

敏化太阳能电池是当前清洁能源领域的研究热点之一,有望成为第三代太阳能电池。二氧化钛作为敏化太阳能电池的光阳极材料之一被广泛研究。主要综述了近20 a来二氧化钛光阳极材料的结构进展,并从电子注入效率、电子传输和基底电荷收集效率方面评述了各种结构的应用特点。另外,描述了当代三明治状二氧化钛工作电极的超薄保形覆盖层、工作层和阻挡层。然后,重点介绍了用于电子传输工作层的二氧化钛一维纳米阵列的制备方法及特点。最后,展望了光阳极结构与合成方法的未来发展趋势。     

Dinaphtho-s-indacene-based copolymers for inverted organic solar cells with high open-circuit voltages

We report on the synthesis and characterization of a series of donor–acceptor copolymers (PF1, PF2, PF3 or PF4) based on a dinaphtho-s-indacene (DNI) donor unit and four different acceptor units. The molecular weights of the copolymers were determined by using gel permeation chromatography, and their electrochemical properties were investigated by cyclic voltammetry. All four copolymers showed deep-lying highest occupied molecular orbital energy levels. Inverted bulk heterojunction solar cells were fabricated by using the synthesized copolymers as the electron donor material and 6,6-phenyl-C71-butyric acid methyl ester (PC₇₁BM) as the electron acceptor material. Inverted solar cells based on PF1:PC₇₁BM (1:4, w/w) exhibited a power conversion efficiency (PCE) of 3.07%, a high open-circuit voltage (V_oc) of 0.99 V, a short-circuit current density (J_sc) of 7.85 mA/cm², and a fill factor of 39.5% under the AM1.5G illumination. With the same fabrication method, the inverted devices based on PF2, PF3 and PF4 showed PCEs of 2.62, 1.18 and 1.32%, and V_oc values of 0.97, 0.91 and 0.80 V, respectively.     

A natural tomato slurry as a photosensitizer for dye-sensitized solar cells with TiO2/CuO composite thin films

We have studied the performance of dye-sensitized solar cells by employing natural dye “anthocyanins” extracted from the tomato slurry as a sensitizer for the TiO₂/CuO photoanode. The extracts were anchored on TiO₂/CuO films deposited on an ITO substrate which was used as a photoanode. The dye adsorbed TiO₂/CuO films electrode, the copper plate as a counter electrode, and iodolyte as an electrolyte were assembled into DSSCs. The conversion efficiency of the DSSCs was found to be 2.96% with a V_OC of 0.615 V, J_SC of 6.6 mA/cm², and an FF of 0.73. This work highlights the use of contribution of the tomato slurry as a natural sensitizer to enhance the efficiency of DSSCs.     

Improving the performance of inverted organic solar cells by embedding silica‐coated silver nanoparticles deposited by electron‐beam evaporation

Embedding metallic nanoparticles (MNPs) in organic solar cells (OSCs) is proposed as one of the promising strategies to enhance their photovoltaic performance owing to localized surface plasmon resonance, light scattering effects or a synergy of both effects derived from the MNPs. However, it has been demonstrated that MNPs wrapped by a thin dielectric silica shell can lead to better photovoltaic yield than bare MNPs due to the presence of the dielectric shell which avoids direct contact between the active layer and the MNPs, reducing the charge recombination and the exciton quenching loss at the metal surface. In this study, we report an alternative solution using an ultrathin dielectric layer coating silver nanoparticles (Ag NPs) for improving the performance of plasmonic inverted OSCs instead of the use of metal–dielectric core–shell NPs. A silica (SiO₂) layer 5 nm thick coating evaporated Ag NPs with an average size of 60 nm is deposited on top of the zinc oxide (ZnO) layer used as the electron transport layer, leading to a significant improvement in the short‐circuit current density (J_sc) and the power conversion efficiency (PCE) of the inverted OSCs. The electron‐beam evaporation method is employed for controlled deposition of Ag NPs and SiO₂ on the ZnO layer. The plasmonic devices resulted in an 18% and 14.1% enhancement of the J_sc and PCE, respectively, compared to reference devices. This increase of the photoelectric parameters in plasmonic devices is attributed not only to the plasmonic effects originating from the Ag NPs but also to the ultrathin silica layer which can contribute to facilitating charge extraction. © 2019 Society of Chemical Industry