Optical and Electrical Characterization and Performance of Roselle and Helba Dyes Using Sensitized Nanosolar Cells

Abstract

Solar cells represent now a dream of physicists and people to solve the energy problem. Silicon solar cells which are now a day widely used suffer from noticeable problems, like high cost and complex fabrication. There is a need for new solar cells types which are cheap and easy to fabricate. The most promising . (type is the dye sensitized nanosolar cells (photoelectrodye Natural Roselle anthocyanin and Helba carotenoid dye were extracted by solvent extraction, so as to be employed as a sensitizer in dye sensitized solar cells (DSSCs). The optical properties of the dye Roselle anthocyanins shows high absorption to visible spectrum which shows high concentration of anthocyanin in Roselle calyces and high efficiency in absorbing light. Its absorption to sun light is almost constant which indicates high chemical stability. The absorption spectrum of the anthocyanin dye dissolved in methanol shows in the UV region, while shows in the VIS range. The absorption spectrum of fresh and crude Roselle shows in the UV region in the visible region, in the UV region, while shows in the VIS range respectively, the absorption spectrum of the carotenoid dye and crude Helba dissolved in methanol also shows in the UV region, while shows in .the VIS range, in the UV region, while shows in the VIS range respectively The response of optical absorption to temperature shows stability at ambient temperature, while absorption decreases as temperature increases above ambient .temperature In this work 10 dye cells are prepared with ITO glass acting as a substrate coated with and anthocyanin dye. The performance and efficiency of these 10 cells were studied by changing the concentration of anthocyanin dye 10 times. Each cell is characterized by a certain dye concentration ranging from 1 up to 10g/4cm 2 in steps of 1g/4cm2. The performance of these cells are investigated by increasing voltages and the corresponding currents generated by these cells, then displaying the V-I characteristic curves. It was found that the efficiency of the dye cells increases gradually by increasing dye concentration till it attains max value of .13% when the concentration is 6 g/4cm2 then it drops again to a minimum value The same procedures are made for Helba. The efficiency of the dye cells increases gradually by increasing dye concentration till it attains max value of 6.9% at the concentration of 8 g/4cm2. Generally the efficiency of anthocyanin cell is relatively . larger than of carotenoid There is a clear difference in the efficiency of cells fabricated from pure dye (anthocyanins or carotenoids), compared with fresh and crude dyes. The efficiency .of pure dye cells are higher Keywords: Dye-sensitized, photoelectrodye, Nanosolar, anthocyanin, Carotenoid .Concentration, spectrum