Article Sidebar
Published:
Feb 18, 2015Keywords:
Article Details
Open access articles published in the Journal of Agriculture, Science and Technology are under the terms of the Creative Commons Attribution (CC BY) License which permits use, distribution and reproduction in any medium, provided the original work is properly cited. The CC BY license permits commercial and non-commercial re-use of an open-access article, as long as the author is properly attributed.
Copyright on any research article published in the Journal of Agriculture, Science and Technology is retained by the author(s). The authors grant the Journal of Agriculture, Science and Technology with a license to publish the article and identify itself as the original publisher. Authors also grant any third party the right to use the article freely as long as its original authors, citation details and publisher are identified.
Use of the article in whole or in part in any medium requires proper citation as follows:
Title of Article, Names of the Author, Year of Publication, Journal Title, Volume (Issue) and page. Links to the final article on the JSRE website are encouraged.
The Creative Commons Attribution License does not affect any other rights held by authors or third parties in the article, including without limitation the rights of privacy and publicity. Use of the article must not assert or imply, whether implicitly or explicitly, any connection with, endorsement or sponsorship of such use by the author, publisher or any other party associated with the article.
For any reuse or distribution, users must include the copyright notice and make clear to others that the article is made available under a Creative Commons Attribution license, linking to the relevant Creative Commons web page. Users may impose no restrictions on the use of the article other than those imposed by the Creative Commons Attribution license.
To the fullest extent permitted by applicable law, the article is made available as is and without representation or warranties of any kind whether express, implied, statutory or otherwise and including, without limitation, warranties of title, merchantability, fitness for a particular purpose, non-infringement, absence of defects, accuracy, or the presence or absence of errors.
Main Article Content
The absorption spectra of natural dyes and their suitability as a sensitiser in organic solar cell application
Abstract
This paper analyzes the suitability of organic dyes (hibiscus, Solanum nigrum, beetroot and eggplant) that are locally available in East Africa for low-budget dye sensitized solar cells (DSSC). The natural dyes were extracted in different ways, where the nightshade berries and eggplant were simply crushed and sieved to obtain their juices, while for hibiscus and beetroot, the fruits was boiled in water and then ethanol. The most promising results are found from hibiscus extracted in water at 50°C, which exhibit a significantly better performance in Umpp (311.35mV),
Impp (236.43.A) and efficiency (0.43%). The results also show that Solanum nigrum is strong in terms of voltage but poor in terms of current, while Eggplant fails due to a difficult extraction process. Beetroot turns out to be a poor candidate since it contains betanin which does not chelate to the TiO2 surface of the cell. The analysis of Solanum nigrum and hibiscus mixture shows that these mixtures do not lead to a better performance. It is also observed that the process of chelating to the TiO2 shifts the absorption spectra of the dyes slightly towards lower wavelengths. The analysis of the molecular structures of betanin and certain anthocyanins shows the number of =O and -OH groups relative to the total number
of atoms per molecule is higher for most anthocyanins, so that they can connect better to TiO2 than betanin.
Key words: Dye-sensitised solar cells, hibiscus, Solanum nigrum, beetroot, eggplant, complex dye- molecules
