染料敏化太阳能电池电子传输的数值模拟研究

基于电子传输的扩散理论建立了染料敏化太阳能电池(DSSC)的连续性方程,使用适合于二氧化钛(TiO₂)作为光阳极的内部参数,对DSSC电子注入和传输的内在机理进行研究。分别考查温度、TiO₂膜厚、电子寿命、电子扩散系数、光照强度、吸收系数等因素对DSSC光电性能的影响,为DSSC性能的改进及光电转换效率的提高提供理论指导。     

染料敏化太阳能电池研究进展

染料敏化太阳能电池(DSSC)是一种新型光电化学太阳能电池,它具有生产成本低、制作工艺简单、原材料来源丰富以及环保等优点。介绍了染料敏化太阳能电池的一般结构及原理,综述了现阶段国内外对染料敏化太阳能电池中光阳极、敏化剂、对电极、电解质、光谱吸收等因素的最新研究进展,并对目前染料敏化太阳能电池中光阳极、染料、电解质、层叠结构等方面存在的问题及发展前景进行了阐述,最后总结了染料敏化太阳能电池的发展方向。     

染料敏化太阳能电池的研究进展

简要介绍了染料敏化太阳能电池的结构及工作原理;综述了染敏太阳能电池的最新研究成果.对染料敏化太阳能电池电极材料、染料敏化剂、电解质等组件及其关键技术的研究进行了详细地评述.指出了染料敏化太阳能电池研究中存在的问题.对该技术领域未来发展前景做了展望.     

太阳能电池的研究现状与发展趋势

针对目前太阳能电池中占重要地位的硅太阳能电池、化舍物半导体和染料敏化太阳能电池的研究现状进行了调研,对研究热点、存在问题及发展方向进行了总结,同时讨论了三类太阳能电池各自的优势和不足.     

CdS量子点敏化TiO_2纳米颗粒多孔薄膜太阳能电池性能研究

以CdS量子点敏化TiO2纳米颗粒多孔薄膜为光阳极,与多硫电解液和Pt对电极组装太阳能电池,研究了光阳极厚度和敏化周期对光伏性能的影响。结果表明,TiO2纳米颗粒多孔薄膜的最佳厚度为14μm,最佳CdS量子点敏化周期为20,由此得到的太阳能电池的短路电流密度J sc、光电转换效率η和量子效率分别为4.51 mA/cm2、0.76%和69%。在光阳极中采用TiO2纳米颗粒/TiO2纳米线多孔薄膜双层工作电极,TiO2纳米线散射层增加了对入射光的利用率,使电池在可见光波段的量子效率增加,从而使电池的短路电流密度J sc和光电转换效率分别比原来提高了11.6%和10.5%。     

扩散波模型在城市坡面汇流中的应用

为分析一维扩散波水动力方程在模拟城市地表降雨径流过程中的可行性,针对典型概化城市流域,采用一维扩散波水动力方程的数值解法模拟了一短历时强降雨事件,并对比SWMM模型模拟结果与扩散波模型模拟结果。结果表明,扩散波模型可以较好地体现降雨作用下地表径流过程的动力特点,但无法适用于过缓的地表坡度,解释了两者连续性方程的差异对模拟结果的影响,最后分析了扩散波模型下边界条件的确定方法。研究成果可为城市坡面汇流模拟提供参考。     

染料敏化太阳能电池的发展

简述染料敏化太阳能电池(DSSC)的发展历程,介绍DSSC的结构和基本原理.对DSSC中的几个重要组成部分:纳米半导体薄膜、敏化染料、电解质体系及对电极等几个方面的研究进行评述.总结当前DSSC产业化研究的现状,并指出该领域目前存在的一些问题及面临的挑战.     

美研发成功含有大肠杆菌的生物太阳能电池

正据美国SlashGear报道,美不列颠哥伦比亚大学研究人员近日研发成功一种新的太阳能电池,即使在阴天也能将光转换成能量。与常用的太阳能产品不同,这些新开发的太阳能电池具有生物体,使其具有"生物成因"。据介绍,该电池使用了一种基因工程菌株大肠杆菌,能产生大量的番茄红素——一种天然染料。番茄红素有能力将光转化为能量,为这些新开发的生物太阳能电池铺平了道路。     

利用内光谱响应测量晶体硅太阳电池前表面复合速度

根据发射区电流密度的连续性方程,推导出了发射区杂质服从高斯函数和余误差函数分布情况下短波内光谱响应与前表面复合速度的模型,该模型短波波长的选择与扩散结深有关.并利用该模型对不同扩散条件下的晶体硅太阳电池前表面复合速度进行计算,结果与PC1D模拟结果符合较好.     

阳极氧化法测量硅太阳能电池结深及杂质浓度分布

报道了用四探针法及阳极氧化法测试云南半导体器件帮生产的φ（１００）绒面硅太阳能电池扩散层薄层电阻（Ｒｓ）及结深（Ｘ１）的情况，从中可检测适合于硅太阳能电池ｐ－ｎ结需要的Ｒｓ和ｘ１对提高太阳能电池产品质量有较重要的指导作用。     

Review: Dye sensitized solar cells based on natural photosensitizers

The performance of dye sensitized solar cells is mainly based on the dye as a sensitizer. Natural dyes have become a viable alternative to expensive and rare organic sensitizers because of its low cost, easy attainability, abundance in supply of raw materials and no environment threat. Various components of a plant such as the flower petals, leaves and bark have been tested as sensitizers. The nature of these pigments together with other parameters has resulted in varying performance. This review briefly discusses the emergence, operation and components of dye sensitized solar cells together with the work done on natural dye based dye sensitized solar cells over the years.     

Novel dye based photoelectrode for improvement of solar cell conversion efficiency

We have explored the application of natural dyes extracted from beetroot in Dye sensitized solar cell (DSSC). The main pigment is betacyanin which was obtained by separation and purification from the extract. The photo electrochemical performance of the DSSC based on these dyes showed that the photo voltage and photocurrent 435 mV, 9.86 mA, respectively. The overall conversion efficiency of nano WO₃ coated TiO₂ dye-sensitized solar cells exhibits a higher conversion efficiency of 2.2%. The photo electrochemical performance of beetroot extract demonstrate that betacyanin dye was the most effectual component of the sensitizer for DSSC because of the simple preparation technique, widely available and low cheap cost.     

St. Lucie cherry,yellow jasmine,and madder berries as novel natural sensitizers for dye‐sensitized solar cells

Natural dyes extracted from fruits, vegetables, flowers, and leaves are considered as promising alternative sensitizers to replace synthetic dyes for dye‐sensitized solar cells (DSSCs). Generally, solar activity of natural dyes stem from anthocyanin pigment. Carbonyl, carboxyl, and hydroxyl groups present in the anthocyanin molecule improve the adsorption ability of dye on TiO₂ and therefore facilitate charge transfer. Here, for the first time, novel natural dyes extracted from St. Lucie cherry, yellow jasmine, and madder berries are reported to act as sensitizer in DSSCs. These novel natural dye extracts are prepared by dissolving related fruits in ethanol. The ingredient of the dyes is identified by FT‐IR spectroscopy. Accordingly, FT‐IR spectrum reveals that novel natural dye extracts exhibit all the characteristic peaks of anthocyanin pigment. Specifically, St. Lucie cherry consists of more distinct carbonyl group than other sources. Also, photoanodes composed of three TiO₂ layers are prepared by using a spin‐coating method. Then, they are immersed into natural dyes and analyzed by conducting UV‐Vis spectroscopy. Compared with bare TiO₂, natural dye–loaded photoanodes demonstrate far higher absorption ability in the visible region. After fabrication of devices with different novel natural dye sensitizers, current‐voltage characteristics and electrochemical impedance spectroscopy measurements are performed. The best power conversion efficiency (PCE) of 0.19% is obtained by sensitization of St. Lucie cherry with an open‐circuit voltage (V_oc) of 0.56 V, short‐circuit current density (J_sc) of 181 μA cm^?2, and fill factor (FF) of 0.55. Furthermore, St. Lucie cherry–sensitized devices show the lowest charge transfer and highest recombination resistances. This result can be attributed to the obvious carbonyl group exhibited by St. Lucie cherry.     

Synthesis of TiO2 nanoparticles at low hydrothermal temperature and its performance for DSSC sensitized using natural dye extracted from Melastoma malabathricum L. seeds

Efficiency of a dye‐sensitized solar cell (DSSC) device depends on its semiconductor layer and the sensitizing dye to absorb the light. This work seeks to obtain the best solvent for the natural dye extraction from Melastoma malabathricum L. seeds. The extracted dye is used as sensitizer on TiO₂ nanoparticles produced via hydrothermal but optimized at relatively low temperature. Infrared characterization of the extracted dyes showed differences in functional groups using different solvents, whereas ultraviolet visible examination of the dyes showed differences in intensity along the spectrum ranges of 600 to 400 nm with maximum absorption around 550 to 500 nm. Thermal analysis revealed that the natural dye should be stable around room temperature. Analysis on the synthesized TiO₂ nanoparticles showed that the average crystallite size reported in the previous work is consistent with crystallite sizes observed in the transmission electron microscope images. Photoactivity examination showed that the DSSC sensitized using natural dye extracted with ethanol containing 20% distilled water on TiO₂ synthesized at 150°C has an efficiency of 5.7%, whereas the one on commercial TiO₂ P25 Degussa has an efficiency of 3.0%. The DSSC device sensitized using commercial dye on TiO₂ synthesized at 150°C has an efficiency of 4.4%, whereas the one on TiO₂ P25 Degussa has an efficiency of 4.0%. This result is promising for further development of the DSSC device using TiO₂ nanoparticles synthesized at low hydrothermal temperature and sensitized with the natural dye.     

Enhancement in the photostability of natural dyes for dye‐sensitized solar cell (DSSC) applications: a review

The advancements in the generation of solar cells have created a landmark to design a cost‐effective, less weight, biocompatible, and environmental‐friendly solar cell. Dye‐sensitized solar cells (DSSCs) have become a topic of significant research in the recent years because of their imperative role in the zone of harvesting energy from the renewable source, and it appears to be a promising candidate for the triumph because of its low cost and ease of preparation. The use of synthetic dyes as a sensitizer for DSSC provides better efficiency and high durability. Unfortunately, they suffer from several margins such as higher cost and usage of toxic materials. These downsides have opened up for alternative sensitizer such as biocompatible natural dyes. Natural dyes contain plant pigments such as carotenoid, flavonoid, betalains, and chlorophyll that act as sensitizers (dye) for DSSC. But, the efficiency of natural dyes is not up to the mark mainly due to photoinstability of natural dye in the presence of sunlight that leads to photodegradation. The stability issues are mainly due to interaction of natural dyes with photoelectrode. The photoelectrodes in DSSC are semiconductor materials with superior characteristic of photocatalytic activity (PCA). The PCA of titanium dioxide (TiO₂) generates high energetic free electrons on the surface of film that produce free radical ions in contact with moisture. These free radical ions readily degrade the organic matter present nearby (natural dye in DSSC). Thus, the PCA of photoelectrode is responsible for the photodegradation of dyes causing photoinstability. The main objective of this review is to study the photoinstability of natural dyes in DSSC. In this regard, the DSSC is concentrated into sections, and the stability issues due to PCA of photoelectrode are studied individually in the view of considering the DSSC operating with iodide‐based electrolytes and platinum as counter electrode only. Various algae groups are featured as a study tool to overview the dye interaction with photoelectrode. It highlights the application of Z‐scheme of photosynthesis to DSSC to have a broader perception on the working of DSSC and also shows some of the ways for improving the stability of dyes by suppressing or reducing the PCA of photoelectrode. Copyright © 2017 John Wiley & Sons, Ltd.     

Photosynthesis in a test tube- dye sensitized solar cells as a teaching tool

Dye sensitized solar cells employing natural plant dyes as phosensitizers can be effectively used to train students in the science and technology of solar cells. This is especially relevant to developing countries where facilities for silicon cell fabrication are non-existent. The cross-disciplinary nature of this device makes it very attractive for student projects. The present work describes such a project where anthocyanin dye from hibiscus flowers has been used as the electron harvester.     

Investigation of novel anthracene‐bridged carbazoles as sensitizers and Co‐sensitizers for dye‐sensitized solar cells

Novel anthracene‐bridged carbazole organic dyes (designated ML4 and ML5) were synthesized using the Suzuki coupling reaction. These dyes were designed to be donor‐π‐conjugation‐acceptor sensitizers for dye‐sensitized solar cells, where the carbazole moiety acts as the donor, the anthracene moiety provides the π‐conjugation, and the cyano acrylic acid acts as the acceptor. Solar cells were fabricated with ML4 and ML5 alone with low power conversion efficiencies, but they were also used as co‐sensitizers with N719, improving the efficiency of the dye‐sensitized solar cells produced by ~3% and ~10%, respectively. Copyright © 2015 John Wiley & Sons, Ltd.     

Status and outlook of sensitizers/dyes used in dye sensitized solar cells (DSSC): a review

Dye‐sensitized solar cells (DSSCs) have become a topic of significant research in the last two decades because of their scientific importance in the area of energy conversion. Currently, DSSC is using inorganic ruthenium (Ru)‐based, metal‐free organic dyes, quantum‐dot sensitizer, perovskite‐based sensitizer, and natural dyes as sensitizer. The use of metal‐free, quantum‐dot sensitizer, perovskite‐based sensitizer, and natural dyes has become a viable alternative to expensive and rare Ru‐based dyes because of low cost, ease of preparation, easy attainability, and environmental friendliness. Most of the alternatives to Ru‐based dyes have so far proved inferior to the Ru‐based dyes because of their narrow absorption bands (Δλ ≈ 100–250 nm), adverse dye aggregation, and instability. This review highlights the recent research on sensitizers for DSSC, including ruthenium complexes, metal‐free organic dyes, quantum‐dot sensitizer, perovskite‐based sensitizer, mordant dyes, and natural dyes. It also details and tabulates all types of sensitizer with their corresponding efficiencies. Plot of progress in efficiency (η) of DSSC till date based on different types of sensitizers is also presented. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.     

The synthesis and characterization of carbon dots and their application in dye sensitized solar cell

Carbon dots (CDOTs) are increasingly becoming popular in the areas ranging from sensing and bioimaging to electronics. The interesting optical properties of CDOTs make it vital to explore its potential in the development of sustainable energy. In this work, one-step hydrothermally synthesized CDOTs were used as sensitizing agent in the fabrication of dye sensitized solar cell. The fabrication of the CDOT-based dye sensitized solar cell and its performance characteristics are explored in depth. The fabricated dye sensitized solar cell performance in terms of efficiency, voltage, and current was evaluated using a standard illumination of air-mass 1.5 global (AM 1.5 G) having an irradiance of 100 mW/cm [2]. The photon-to-current conversion efficiency (η) of only the carbon dot sensitized solar cell was 0.10% whereas the efficiency of the solar cell fabricated with a sensitizing dye made up of CDOT and N719 was 0.19%. As compared with the performance DSSCs fabricated with only 719 dye, it was observed that when CDOT was used in combination with N719 as sensitizing dye, the open circuit voltage increases yet the overall efficiency of the resulting solar cells decreases. It is clear from the result that CDOT could be used as a sensitizing dye in DSSCs. However, it is not very useful when used in combination with other sensitizing dyes due to energy transfer.