Guanidinium Iodides-based Ionic Liquids: Synthesis and Application for Dye-sensitized Solar Cells(DSSCs)

A series of guanidinium ionic liquids（GILs） was designed, synthesized, and used as electrolytes for dye-sensitized solar cells（DSSCs）. The effect of electrolytes containing GILs on the photovoltaic performance of DSSCs was investigated. It is demonstrated that these GILs are promising for being used as electrolytes for DSSCs and a conversion efficiency of 4.1% can be obtained under AM 1.5 sun light irradiation.

Synthesis and photophysical properties of donor–acceptor system based bipyridylporphyrins for dye-sensitized solar cells

Bipyridylporphyrin derivatives possessing a porphyrin moiety as the electron donor and bipyridyl moiety as the electron-acceptor were designed and synthesized for dye-sensitized solar cells （DSSCs）. The photo- physical and electrochemical properties were investigated by absorption spectrometry and cyclic voltam- metry. Density functional theory （DFT） was employed to study electron distribution. From the photovoltaic performance measurements, a maximum conversion efficiency （η） of 0.38% was achieved based on the bipyridylporphyrin ruthenium dye A7 （Jsc = 1.33 mA/cm^2, Voc = 0.45 V, FF = 0.64） under 1,5 irradiation （100 mW/cm^2）.

Impact of Dye-Sensitized Solar Cell Anode Preparation on Performance

In this paper, the suitable molecular weight of polyethylene glycol (PEG) and annealing temperature for dye-sensitized solar cells (DSSCs) anode was obtained by assessing the performance of DSSCs. The output current characteristic of the DSSCs is to explore factors that affect cell conversion efficiency and the effect of the mechanism. Experimental results show that the annealing temperature of 500°C and adding PEG of molecular weight 2000, the TiO2 thin film electrode TiO2 film electrode has good optical properties.

基于技术专业化指数的企业技术竞争力评价研究

技术是企业核心能力中最根本的部分,而专利作为技术最重要的载体,逐渐成为诸多国内外学者研究技术竞争力的对象之一。目前国内外基于专利的企业技术竞争力评价并不能全面反映企业技术竞争力的本质。基于跨学科指数测度方法构建了基于专利IPC分类号的技术专业化指数模型,从专利数量和技术专业化指数两个维度建立了企业技术竞争力评价框架,并以染敏太阳能电池技术为实证案例,研究表明该方法可为技术竞争力评价提供一个崭新视角。

Rutile TiO2 Microspheres with Exposed Nano-Acicular Single Crystals for Dye-Sensitized Solar Cells

有暴露的 nano 针状的单个晶体的特别地结构化的金红石 TiO2 microspheres 成功地经由一个灵巧的热水的方法被综合了。在在 450 点的锻烧以后？

TiO_2@MgO Core-Shell Film:Fabrication and Application to Dye-Sensitized Solar Cells

In this study,TiO2@MgO core-shell film was obtained by using a simple chemical bath deposition method to coat a thin MgO film around TiO2 nanoparticles. The core-shell configuration was characterized by X-ray diffractometer (XRD),scanning elec-tron microscopy (SEM),energy dispersive X-ray spectroscopy (EDX),and high-resolution transmission electron microscopy (HRTEM). Lattice fringes were observed for the TiO2 particles,and the MgO shell showed an amorphous structure,revealing a clear distinction between the core and shell materials. Applying the core-shell film as photoanode to the dye-sensitized solar cells (DSSCs),it shows a superior performance compared to the pure TiO2 electrode. Under the illumination of simulated sunlight (75 mW-cm-2),the short circuit photocurrent (Jsc),the open circuit photovoltage (Voc),and the fill factor (fF) are 8.80 mA-cm-2,646 mV,and 0.69,respectively,and the conversion efficiency (η) in-creased by 21.8% (from 4.32% to 5.26%) when dipping for opti-mum condition.

Progress in nanostructured photoanodes for dye-sensitized solar cells

Solar cells represent a principal energy technology to convert light into electricity. Commercial solar cells are at present predominately produced by single- or multi-crystalline silicon wafers. The main drawback to silicon-based solar cells, however, is high material and manufacturing costs. Dye-sensitized solar cells （DSSCs） have attracted much attention during recent years because of the low production cost and other advantages. The photoanode （working electrode） plays a key role in determining the performance of DSSCs. In particular, nanostructured photoanodes with a large surface area, high electron transfer efficiency, and low electron recombination facilitate to prepare DSSCs with high energy conversion efficiency. In this review article, we summarize recent progress in the development of novel photoanodes for DSSCs. Effect of semiconductor material （e.g. TiO2, ZnO, SnO2, N2O5, and nano carbon）, preparation, morphology and structure （e.g. nanoparticles, nanorods, nanofibers, nanotubes, fiber/ particle composites, and hierarchical structure） on photovoltaic performance of DSSCs is described. The possibility of replacing silicon-based solar cells with DSSCs is discussed.

A Composite Photoanode Based on P25/TiO2 Nanotube Arrays/ Flower-Like TiO2 for High-Efficiency Dye-Sensitized Solar Cells

In this work, a three-layer TiO2 composite film consisting of flower-like TiO2 （Flo-TiO2） as overlayer, TiOa nanotube arrays as interlayer and TiO2 nanoparticle （P25） as underlayer was fabricated as the photoelectrode of dyesensitized solar cells （DSSCs）. Due to the introduction of Flo-TiO2, the three-layer composite film has strong lightscattering ability. Then, we have investigated and compared the photoelectric conversion properties of DSSCs based on three-layer structure （P25/TNT arrays/Flo-TiO2） photoelectrode and double-layer film （P25/TNT arrays） photoelectrode. It is found that DSSCs based on three-layer structure exhibit a high power conversion efficiency of 6.48% compared with the DSSCs composed of double-layer film （5.11%）.

ZnO/Nb2O5 core/shell nanorod array photoanode for dye-sensitized solar cells

In this paper, ZnO/Nb2O5 core/shell nanorod arrays were synthesized and used as photoanodes for dye- sensitized solar cells （DSSCs）. We first synthesized ZnO nanorod array on fluorine-doped tin oxide （FTO） glasses by a hydrothermal method, and then ZnO/Nb2O5 core/shell nanorod array was directly obtained via solvothermal reaction in NbCl5 solution. The scanning electron micro- scope （SEM） and transmission electron microscope （TEM） images revealed that the ZnO nanorods were uniformly wrapped by Nb2O5 shell layers with a thickness of 30-40 nm. Photovoltaic characterization showed that the device based on ZnO/Nb2O5 core/shell nanorod photoanode exhibited an improved efficiency of 1.995%, which was much higher than the efficiency of 0.856% for the DSSC based on bare ZnO nanorod photoanode. This proved that the photovoltaic performance of ZnO nanorods could be improved by wrapping with Nb2O5 shells.

Enhanced Efficiency of Dye-sensitized Solar Cells Using rGO@TiO2 Nanotube Hybrids

We established a novel strategy for the synthesis of reduced graphene oxide（rGO）@TiO2 nanotube hybrids using an 18 W UV-assisted photo-catalytic reduction method for utilization as photo-anode of dye-sensitized solar cells（DSSCs）. The photo-conversion efficiency of DSSCs was significantly enhanced after the addition of rGO, and in addition, the photo-anode showed decreased internal resistance. Analysis of rGO@TiO2 hybrids by transmissions scanning electron microscopy（TEM）, X-ray diffraction（XRD）, Raman spectra, N2 adsorption and desorption, atomic force microscopy（AFM） and X-ray photoelectron speetroscopy（XPS） demonstrates that the rGO modified TiO2 nanotubes can increase the short-circuit current and the conversion efficiency of dye-sensitized solar cells. The efficiency is improved by almost two folds as much compared to those of the bare TiO2 nanotubes.

Preparation of titanium dioxide-double-walled carbon nanotubes and its application in flexible dye-sensitized solar cells

Titanium dioxide-double-walled carbon nano- tubes （TiO2-DWCNTs） with DWCNTs/TiO2 of 20 wt.% is prepared by a conventional sol-gel method. Doping the TiO2-DWCNTs in TiO2 photoanode, a flexible dye- sensitized solar cell （DSSC） is fabricated. The sample is characterized by scanning electron microscopy, X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） absorption, ultraviolet-visible spectroscopy （UV- vis） absorption spectra , electrochemical impedance spec- troscopy （EIS） technique and photovoltaic measurement. It is found that adding a certain amount of TiO2-DWCNTs can efficiently decrease the resistance of charge transport, improve dye adsorption. Under an optimal condition, a flexible DSSC contained with 0.50 wt.% TiOz-DWCNTs achieves a light-to-electric energy conversion efficiency of 3.89% under a simulate solar light irradiation of 100 mW. cm^2.

Influence of defect density on the ZnO nanostructures of dye-sensitized solar cells

The relationship between bilayer nanostructure, defect density and dye-sensitized solar cell （DSCC） per- formances was investigated. By adjusting bilayer nano- structures, defect density of ZnO nanodendrite-nanorods structure was decreased comparing to that of nanoflower- nanorods structure. The performances of DSCC based on ZnO nanodendrites-nanorods structure and nanoflower- nanorods structure were studied by Raman spectrum, room temperature photoluminescence, dye loading, photocurrent density-voltage characteristic and open-circuit voltage decay （OCVD） technique. The device with nanodendrite- nanorods structure has lower charge recombination rate and prolonged electron lifetime due to its microstructure feature.

Monolithic all-solid-state dye-sensitized solar cells

As a low-cost photovoltaic technology, dye- sensitized solar cell （DSSC） has attracted widespread attention in the past decade. During its development to commercial application, decreasing the production cost and increasing the device stability take the most impor- tance. Compared with conventional sandwich structure liquid-state DSSCs, monolithic all-solid-state mesoscopic solar cells based on mesoscopic carbon counter electrodes and solid-state electrolytes present much lower production cost and provide a prospect of long-term stability. This review presents the recent progress of materials and achievement for all-solid-state DSSCs. In particular, representative examples are highlighted with the results of our monolithic all-solid-state mesoscopic solar cell devices and modules.

Recent progress on tandem structured dye-sensitized solar cells

Tandem structured dye-sensitized solar cells （DSSCs） can take full advantage of sunlight, effectively broadening the absorption spectrum of the cell, resulting in a higher open circuit voltage or short circuit current than that of the conventional DSSC with single light absorber. The theoretical maximum efficiency is therefore suggested to be over the Schottky-Queisser limit of 33%. Accord- ingly, tandem design of DSSC is thought to be a promising way to break the performance bottleneck of DSSC. Besides, the tandem designs also broaden the application diversity of DSSC technology, which will accelerate its scale-up industrial application. In this paper, we have reviewed the recent progress on photo-electrochemical applications associated with kinds of tandem designs of DSSCs, in general, which are divided into three kinds： ＂n- type DSSC ＋ n-type DSSC,＂ ＂n-type DSSC ＋ p-type DSSC＂ and ＂n-type DSSC ＋other solar conversion devices.＂ The working principles, advantages and chal- lenges of these tandem structured DSSCs have been discussed. Some possible solutions for further studies have been also pointed out together.

天然染料作为Zn_2TiO_4太阳能电池敏化剂的研究

从植物的叶、花、果实和果皮中提取出7种天然染料,通过对它们的UV-vis吸收光谱比较发现,从月季叶中提取的染料表现出较好的光响应性。采用溶胶-凝胶法制备了纳米晶Zn2TiO4薄膜电极,并利用X射线衍射(XRD)、扫描电镜(SEM)对其晶相及表面形貌进行了表征;制备了月季叶染料敏化Zn2TiO4电极,并以此为光阳极组装了Zn2TiO4太阳能电池;测定了上述敏化电极的吸收光谱以及电池的工作特性曲线。结果表明,月季叶染料吸附到Zn2TiO4薄膜上与染料在乙醇溶液中相比较,染料的吸收带变宽且最大吸收波长向红外方向发生了移动,月季叶染料在与Zn2TiO4结合后表现出一定的电子转移特性,并能很好地敏化Zn2TiO4电极;在模拟太阳光下,该电池开路电压为94.5 mV,短路电流为11.5μA,填充因子0.285和最大输出功率为0.309μW。

Multispectral Plasmon of Anisotropic Core-shell Gold Nanorods@SiO2： Dual-band Absorption Enhancement with Coupling Dye Molecules

Direct evidence of effects of surface plasmon resonance（SPR） of gold naaorods（GNRs） on dual-band light absorption enhancement with coupling dye molecules was reported by introducing gold nanorod@SiO2（GNR@SiO2） core-shell nanoparticles into a photoelectric conversion system. GNR with asymmetric shape had unusual anisotropic SPR[transversal surface plasmon resonance（TSPR） and longitudinal surface plasmon resonance（LSPR）]. The excel- lent SPR of GNR made it a promising candidate as enhancing light absorption material to increase power conversion efflciency（PCE）. The PCE was improved nearly 17.2% upon incorporating GNRs, mostly due to the increase in Jsc, while Vo~ and FF were unchanged. The improvement was mostly contributed by the SPR of the GNRs with coupling of N719. And there was also a complementary to N719 in visible light range. Therefore, SPR is an effective tool in improving the photocurrent and consequently enhancement of PCE. The TSPR and LSPR effects of GNRs on light harvesting were reflected in the increased monochromatic incident photon-to-electron conversion efficiency（IPCE）. We also utilized finite-difference tirne-domain（FDTD） to investigate the light coupling of GNRs with TiO2. Compare to the base anode, the IPCE of optimized electrode showed significant improvement and peaks broadening at 500--600 nm and 610--710 nm. We got an increase in overall conversion efficiency from 6.4% to 7.5%.

Effect of electron-withdrawing groups in conjugated bridges： molecular engineering of organic sensitizers for dyesensitized solar cells

Four organic sensitizers containing quinoxaline or benzoxadiazole as an auxiliary electron acceptor in conjugated bridge were synthesized and utilized for dyesensitized solar cells （DSSCs）. It was found that the incorporation of different electron-withdrawing moieties can affect the absorption spectra, electronic properties, the interfacial interactions and then the overall conversion efficiencies significantly. Therefore, the appropriate selection of the auxiliary acceptor was important to optimize the photovoltaic performance of solar cells. Among these sensitizers, LI-44 based solar cell showed the best photovoltaic performance： a shortcircuit photocurrent density （Jsc） of 13.90 mA/cm2, an open-circuit photovoltage （Voc） of 0.66 V, and a fill factor （FF） of 0.66, corresponding to an overall conversion efficiency of 6.10% under standard global AM 1.5 solar light conditions.