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1.
Replacing the liquid electrolytes in dye-sensitized solar cells (DSCs) with solid-state hole-transporting materials (HTMs) may solve the packaging challenge and improve the long-term stability of DSCs. The efficiencies of such solid-state DSCs (ss-DSCs), however, have been far below the efficiencies of their counterparts that use liquid electrolytes, primarily due to the challenges in filling HTMs into thick enough sensitized films based on sintered TiO(2) nanoparticles. Here we report fabrication of high-efficiency ss-DSCs using multilayer TiO(2)-coated ZnO nanowire arrays as the photoanodes. The straight channel between the vertically aligned nanostructures combined with a newly developed multistep HTM filling process allows us to effectively fill sensitized films as thick as 50 μm with the HTMs. The resulting ss-DSCs yield an average power conversion efficiency of 5.65%. 相似文献
2.
A 3D ZnO nanowire-based dye-sensitized solar cell (DSSC) with unique "caterpillar-like" structure was designed. Because of the significant improvement of the total ZnO nanowire surface area, the amount of light absorption was substantially increased. This increase in the light harvesting efficiency enables us to achieve an overall power conversion efficiency as high as 5.20%, which is the highest reported value to date for ZnO nanowire-based DSSCs. A branched-multilayered design of ZnO nanowire arrays grown from ZnO nanofiber seed layers proves to be very successful in fabricating 3D ZnO nanowire arrays. Practically, electrospun ZnO nanowires were used as the seeds in multilayer growth of ZnO nanowire arrays with a unique "caterpillar-like" structure. This unique structure significantly enhances the surface area of the ZnO nanowire arrays, leading to higher short-circuit currents. Additionally, this design resulted in closer spacing between the nanowires and more direct conduction pathways for electron transfer. Thus, the open-circuit voltage was so significantly improved as a direct result of the reduction in electron recombination. 相似文献
3.
We introduce high surface area ZnO nanotube photoanodes templated by anodic aluminum oxide for use in dye-sensitized solar cells (DSSCs). Atomic layer deposition is utilized to coat pores conformally, providing a direct path for charge collection over tens of micrometers thickness. Compared to similar ZnO-based devices, ZnO nanotube cells show exceptional photovoltage and fill factors, in addition to power efficiencies up to 1.6%. The novel fabrication technique provides a facile, metal-oxide general route to well-defined DSSC photoanodes. 相似文献
4.
Fabrication of ZnO nanowire arrays by cycle growth in surfactantless aqueous solution and their applications on dye-sensitized solar cells 总被引:1,自引:0,他引:1
Guomin Hua Ye Zhang Junxi Zhang Xueli Cao Wei Xu Lide Zhang 《Materials Letters》2008,62(25):4109-4111
Large-scale ZnO nanowire arrays vertically aligned on the substrates were achieved from cycle growth without surfactants. The 8 μm long ZnO nanowire arrays were prepared by 20 cycles. The aspect ratio of ZnO nanowire can be increased with increasing the growth cycle. As displayed by microstructures and photoluminescence (PL) analysis, the ZnO nanowire was good single crystal and the defects in the as-prepared ZnO nanowire arrays were controlled at a low concentration. By increasing the length and aspect ratio of ZnO nanowire, the performances of dye-sensitized solar cells based on the ZnO nanowire arrays were improved. As-prepared ZnO nanowire arrays have potential applications in fabricating next generation nanodevices. 相似文献
5.
Youngjin Chae Jung Tae Park Jong Kwan Koh Jong Hak Kim Eunae Kim 《Materials Science and Engineering: B》2013,178(17):1117-1123
An all-solid, flexible solar textile fabricated with dye-sensitized solar cells (DSSCs) woven into a satin structure and transparent poly(ethylene terephthalate) (PET) film was demonstrated. A ZnO nanorod (NR) vertically grown from fiber-type conductive stainless steel (SS) wire was utilized as a photoelectrode, and a Pt-coated SS wire was used as a counter electrode. A graft copolymer, i.e. poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) was synthesized via atom transfer radical polymerization (ATRP) and used as a solid electrolyte. The conditions for the growth of ZnO NR and sufficient dye loading were investigated to improve cell performance. The adhesion of PET films to DSSCs resulted in physical stability improvements without cell performance loss. The solar textile with 10 × 10 wires exhibited an energy conversion efficiency of 2.57% with a short circuit current density of 20.2 mA/cm2 at 100 mW/cm2 illumination, which is the greatest account of an all-solid, ZnO-based flexible solar textile. DSSC textiles with woven structures are applicable to large-area, roll-to-roll processes. 相似文献
6.
Determination of the effects of ZnO nanowires on the efficiency of ZnO nanowire-based dye-sensitized solar cells (DSSCs) is important. In this study, we determined the effects of different OH- precursors, concentrations, the ratio of zinc nitrate to hexamethylene tetramine (HMT), and the hydrothermal synthesis temperature on the physical, crystal, and optical properties of ZnO nanowires and investigated the performance of the resulting DSSCs. We observed that ZnO nanowires synthesized using an equimolar ratio of HMT to zinc nitrate yielded a DSSC with high incident photon-to-current efficiency (IPCE), cell efficiency, short circuit current density (Jsc), and fill factor (FF), and low ZnO-dye-electrolyte interface resistance due to an increased amount of dye and a decreased density of defects. Furthermore, ZnO nanowires made using optimal concentrations and ratios of zinc nitrate to HMT had a high surface area and low defect density. All the photovoltaic performance parameters of DSSCs assessed such as IPCE, cell efficiency, Jsc, open circuit potential (Voc), and FF increased with synthesis temperature, which was related to a decrease in the resistance at the ZnO-dye-electrolyte interface. We attributed these results to an increased amount of dye facilitated by a large nanowire surface area and fast electron transfer because of the improved crystalline structure of the ZnO nanowires and their low defect density. By optimizing the ZnO nanowires, we increased DSSC efficiency to 0.26% using ZnO nanowires synthesized with 25 mM of both zinc nitrate and HMT at 90 °C, while only a 0.02% increase in efficiency was obtained when NH4OH was used as OH− precursor. 相似文献
7.
High quality, large area and well-oriented ZnO nanorod arrays electrodes were successfully synthesized on conductive transparent oxide substrates by low-temperature hydrothermal methods for dye-sensitized solar cells. Aiming at getting further enhancement and study the effect of the surface modification on cell performance, ZnO thin film and ZnO nanoparticles are carried out to modify the as-grown ZnO nanorod arrays. The morphology, structure and photoluminescence property of the modified ZnO electrodes are characterized in detail. Furthermore, the I-V characterization result shows that these modification methods have distinct influences on the performance of the cell based on ZnO nanorod arrays electrode. The overall conversion efficiency can be optimized by choosing the suitable modification route. 相似文献
8.
Jun Liu Aixiang Wei Zengxian Ge Wang Zhao 《Journal of Materials Science: Materials in Electronics》2013,24(2):542-547
Highly oriented single-crystalline TiO2 nanowire bundle arrays on transparent conductive fluorine-doped tin oxide substrates are prepared by hydrothermal method using the precursors of titanium butoxide, deionized water and hydrochloric acid. The structure and morphology characteristics of all the samples have been analyzed by X-ray diffraction (XRD), scanning electron microscopy and transmission electron microscopy. Results show that the diameter, length, and density of the nanowire bundle arrays can be varied by changing the growth parameters, such as growth time, initial reactant concentration and acidity. The enhanced (002) peak in XRD patterns indicate that the nanowire is well crystallized and grow perpendicular to the substrate. The high resolution transmission electron microscope images and selected-area electron diffraction patterns confirm that there are approximately 10–30 nanowires in each bundle. The nanowire is single crystalline. Dye-sensitized solar cells assembled from oriented TiO2 nanowire bundle arrays as the photoanode are studied. The light-to-electricity conversion efficiency is about 2.17 %. 相似文献
9.
Phathaitep Raksa 《Thin solid films》2009,517(17):4741-4744
The ZnO dye-sensitized solar cells (DSSCs) with different photoelectrodes were studied on the effect of CuO layer as a barrier layer toward power conversion characteristics. The structures of DSSCs based on ZnO as a photoelectrode, Eosin-Y as a dye sensitizer, iodine/iodide solution as an electrolyte and Pt/FTO as a counterelectrode. CuO powder, nanowire prepared by oxidation reaction of copper powder and CuO thin film prepared by evaporation copper thin film, were used as a layer on the top of ZnO layer to form blocking layer. The photocurrent, photovoltage and power conversion efficiency characteristics for DSSCs were measured under illumination of simulated sunlight obtained from a solar simulator with the radiant power of 100 mW/cm2. It was found that ZnO DSSCs with CuO thin film exhibited highest current density of 5.10 mA/cm2 and highest power conversion efficiency of 0.92% than those of CuO powder and nanowire. The enhancement of the power conversion efficiency can be explained in terms of the retardation of the interfacial recombination dynamics of CuO blocking layer. 相似文献
10.
Liu L Chen Y Guo T Zhu Y Su Y Jia C Wei M Cheng Y 《ACS applied materials & interfaces》2012,4(1):17-23
Heterostructured ZnO/ZnS core/shell nanowire arrays have been successfully fabricated to serve as photoanode for the dye-sensitized solar cells (DSSCs) by a facile two-step approach, combining hydrothermal deposition and liquid-phase chemical conversion process. The morphology evolution of the ZnS coated on the ZnO nanowires and its effect on the performance of the DSSCs were systematically investigated by varying the reaction time during the chemical conversion process. The results show that the compact ZnS shell can effectively promote the photogenerated electrons transfer from the excited dye molecules to the conduction band of the ZnO, simultaneously suppress the recombination for the injected elelctrons from the dye and the redox electrolyte. As reaction time goes by, the surface of the nanowires becomes coarse because of the newly formed ZnS nanoparticles, which will enhance the dye loading, resulting in increment of the short-circuit current density (J(SC)) . Open-circuit photovoltage decay measurements also show that the electron lifetime (τ(n)) in the ZnO/ZnS core/shell nanostructures can be significantly prolonged because of the lower surface trap density in the ZnO after ZnS coating. For the ZnO/ZnS core/shell nanostructures, the J(SC) and η can reach a maximum of 8.38 mA/cm(2) and 1.92% after 6 h conversion time, corresponding to 12- and 16-fold increments of as-synthesized ZnO, respectively. 相似文献
11.
The structure of fibrous dye-sensitized solar cells, which were constructed by a TiO(2) nanotube array on Ti wire as the photoanode twisted by a Pt wire counter electrode, has been first systematically investigated by accurately controlling the thread pitch distance of screwed Pt wire. It has been revealed that the thread pitch will strongly influence the photovoltaic performance and kinetic processes in fibrous solar cells. The effect of the length of the TiO(2) nanotube on cell performance has also been discussed. After optimization, a relatively universal optimized thread pitch value of 1 mm for fibrous DSCs has been proved and the light-to-electricity conversion efficiency has been remarkably improved to 5.84%. 相似文献
12.
One-dimensional semiconductor nanostructures grown directly onto transparent conducting oxide substrates with a high internal surface area are most desirable for high-efficiency dye-sensitized solar cells (DSSCs). Herein, we present a multicycle hydrothermal synthesis process to produce vertically aligned, single crystal rutile TiO(2) nanowires with different lengths between 1 and 8 μm for application as the working electrode in DSSCs. Optimum performance was obtained with a TiO(2) nanowire length of 2.0 μm, which may be ascribed to a smaller nanowire diameter with a high internal surface area and better optical transmittance with an increase in the incident light intensity on the N719 dye; as well as a firm connection at the FTO/TiO(2) nanowire interface. 相似文献
13.
采用化学气相沉积(CVD)法制备了不同尺寸的四脚状纳米ZnO和ZnO纳米棒。采用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)对纳米ZnO的晶型结构和形貌进行表征,研究结果表明CVD法制备的四脚状纳米ZnO具有三维空间结构,其最小平均臂宽约为70nm,臂长约300nm,制备的纳米棒直径约为84nm,长约2μm,且都为六方纤锌矿晶型结构。将ZnO纳米四脚状及纳米棒利用滚涂法在FTO导电玻璃上形成ZnO光阳极,经N719染料敏化后组装成染料敏化太阳能电池,光电性能结果表明,染料敏化小尺寸的四脚状纳米ZnO太阳能电池光电转换效率(η=1.88%)高于染料敏化大尺寸的四脚状纳米ZnO太阳能电池光电转换效率(η=1.18%),远高于染料敏化ZnO纳米棒太阳能电池的光电转换效率(η=0.7%)。 相似文献
14.
Yuan GD Zhang WJ Jie JS Fan X Zapien JA Leung YH Luo LB Wang PF Lee CS Lee ST 《Nano letters》2008,8(8):2591-2597
Well-aligned ZnO nanowire (NW) arrays with durable and reproducible p-type conductivity were synthesized on alpha-sapphire substrates by using N2O as a dopant source via vapor-liquid-solid growth. The nitrogen-doped ZnO NWs are single-crystalline and grown predominantly along the [110] direction, in contrast to the [001] direction of undoped ZnO NWs. Electrical transport measurements reveal that the nondoped ZnO NWs exhibit n-type conductivity, whereas the nitrogen-doped ZnO NWs show compensated highly resistive n-type and finally p-type conductivity upon increasing N2O ratio in the reaction atmosphere. The electrical properties of p-type ZnO NWs are stable and reproducible with a hole concentration of (1-2) x 10(18) cm(-3) and a field-effect mobility of 10-17 cm2 V(-2) s(-1). Surface adsorptions have a significant effect on the transport properties of NWs. Temperature-dependent PL spectra of N-doped ZnO NWs show acceptor-bound-exciton emission, which corroborates the p-type conductivity. The realization of p-type ZnO NWs with durable and controlled transport properties is important for fabrication of nanoscale electronic and optoelectronic devices. 相似文献
15.
Yufu Zhu Fei Deng Chaoying Ni Wenzhong Shen 《Journal of Materials Science: Materials in Electronics》2014,25(10):4547-4552
Novel ZnO core/shell nanostructures were constructed by depositing a porous ZnO layer directly on the surfaces of pre-fabricated ZnO nanowires through a facile chemical method. The morphology and structure of the obtained products have been investigated by field-emission scanning electron microscopy, high-resolution transmission electron microscopy and X-ray diffraction analysis. In these unique nanostructures, the porous overlayer exhibits a large surface area for sufficient dye loading to enhance light harvesting and the ZnO nanowire cores provide direct conduction pathways for the photogenerated electron transport to diminish the chance of electron recombination. The obtained ZnO nanostructures were used as photoanode material in dye-sensitized solar cell which showed an increase in performance of 141 % compared with an equivalent solar cell employing ZnO nanowire arrays as photoanode. This result was achieved mainly due to an increase in photogenerated current density directly resulting from improved light harvesting of the porous layer. 相似文献
16.
de Gonçalves AS Davolos MR Nogueira AF 《Journal of nanoscience and nanotechnology》2010,10(10):6432-6438
Well-aligned ZnO nanorod films were grown onto transparent conducting substrates by using an aqueous solution route. The presence of some reflections in the X-ray diffraction pattern of the ZnO films indicates the vertical alignment of the nanorods along the c axis of the wurtzite hexagonal structure. Well-aligned ZnO nanorods were observed by scanning electron microscopy. The presence of top ZnO microflower layers over the ZnO nanorod film was observed for all growth times studied. The ZnO nanorods with ZnO microflower top layers were applied as photoelectrodes in dye-sensitized solar cells. Higher photocurrent densities and photovoltages were observed with longer nanorod growth times. The high performance of the dye-sensitized solar cells might be associated to the combination of ZnO nanorods and microflowers in the same photoelectrode. 相似文献
17.
Ying-Song Fu Jing Sun Yang Xie Jim Liu Hong-Li Wang Xi-Wen Du 《Materials Science and Engineering: B》2010,166(3):196-202
Uniform hierarchical ZnO nanostructures are synthesized on a large scale based on a solution approach at low temperature. The primary ZnO hexagonal prisms are firstly produced by the reaction of Zn(NO3)2 with hexamethylenetetramine, and then ZnO branches grow on the primary prisms by using ethylenediamine molecules as an evocator. The morphology of the hierarchical nanostructure can be controlled conveniently by adjusting the molar ratio of [EDA]/[Zn2+]. The hierarchical structure provides an effective pathway for carrier transport as well as larger surface area for dye adsorption, when ZnO hierarchical nanostructures serve as photoanode materials, the solar cells show higher conversion efficiency than that of primary ZnO nanowires. 相似文献
18.
For the first time, the TiO2 nanorod arrays have been prepared on ITO substrates at room temperature by dc reactive magnetron sputtering technique. These TiO2 nanorods have a preferred orientation along the (220) direction and are perpendicular to the ITO substrate. Both the X-ray diffraction and Raman scattering measurements show that the highly ordered TiO2 nanorod arrays have an anatase crystal structure. The diameter of the nanorod varies from 30 nm to 100 nm and the nanorod length can be varied from several hundred nanometers to several micrometers depending on the deposition time. The TiO2 nanorod arrays with about 3 micrometers length have been used as an electrode for dye-sensitized solar cell (DSSC). Short-circuit photocurrent density, open-circuit voltage, fill factor and light-to-electricity conversion efficiency at 100 mW/cm2 light intensity are estimated to be 12.76 mA/cm2, 0.65 V, 0.63 and 5.25%, respectively, for the DSSC made of the TiO2 nanorods. 相似文献
19.
采用光刻和射频磁控溅射技术在Si衬底上制备了图形化的ZnO种子层薄膜。分别采用气相榆运和水热合成法,制备了最小单元为30μm的图形化的ZnO纳米线阵列。X射线衍射(XRD)分析显示单晶纳米线阵列具有高度的c轴[001]择优取向生长性质,从扫描电子显微镜(SEM)照片看出,阵列图形完整清晰,边缘整齐,纳米线阵列在室温下光致发光(PL)谱线中在380hm左右具有强烈的紫外发射峰,可见光区域发射峰得到了抑制,证明ZnO纳米线阵列氧空位缺陷少,晶体质量高。 相似文献
20.
Two indoline dyes, coded D149 and D205, were used as the sensitizers of ZnO dye-sensitized solar cells (DSCs) with optimal energy conversion efficiencies of more than 5%, under AM 1.5 full sunlight illumination (100?mW?cm( - 2)). Higher interfacial charge transfer rate and retardant fluorescence decay confirmed from transient fluorescence illustrated that D205-sensitized ZnO DSCs could possess better electron transport than D149-sensitized ZnO DSCs. The enhancement of V(oc) and J(sc) for D205-sensitized ZnO DSCs was ascribed to the effective suppression of electron recombination by extending the alkyl chain on the terminal rhodanine moiety from ethyl to octyl. The evidence of enhanced electron diffusion coefficient was further shown by electrochemical impedance spectroscopy (EIS). 相似文献