International Journal of Scientific & Engineering Research, Volume 7, Issue 5, May-2016 345 ISSN 2229-5518 IJSER © 2016 http://www.ijser.org Photoanode Thickness and Sensitization Time Effects on Overall Performance of Nanocrystalline TiO2 Based Solar Cell Sensitized with Roselle Flower Extracts Sanusi Y.K, Kazeem A.A and Suleman K.O Department of Pure and Applied Physics, Faculty of Pure and Applied Sciences, Ladoke Akintola University of Technology, PMB 400 Ogbomoso Nigeria. Abstract: Semiconducting anode layer thickness and anode sensitization time are two major factors that can affect the overall responses of dye sensitized solar cells. By setting these fabrication parameters at different levels, different DSSCs were fabricated at different experimental conditions. FTO conductive glasses were used as substrates and counter electrode fabrication and Roselle flower extract was the chosen as sensitizer. Each cell was illuminated with constant light intensity of 1 Sun (100mW/cm2) A.M 1.5 to determine the photovoltaic responses. A maximum conversion efficiency and fill factor obtained are 0.3220% and 0.7501 respectively. Hence, optimum values of the two parameters investigated favour performance of dye-sensitized solar cells. Keywords: Solar cell, photoanode thickness, sensitization time, natural dye, efficiency, Corresponding Author: Sanusi Y .K. yksanusi@lautech.edu.ng ——————————  —————————— Introduction The conversion of solar energy to electricity has become more and more important, because solar radiation coming from sun is a clean and abundant energy source compared to the fossil fuel source (Gratzel, 2013). Solar energy technologies such as solar cells have been recorded significant progress. Solar cells are categorized into three generations based on their performance and cost effectiveness. The first generation of solar cells has a relatively higher efficiency but plagued with expensive production cost. Photo-generated electron-hole pair is separated and collected through the p-n junction of a doped semiconductor, mainly silicon 1 . The commercial market is dominated by this generation. Thin film solar cells based on CdTe or Cu(InGa)Se 2 make up the 2nd generation cells. They have a lower efficiency, but are much cheaper to produce and employ a less extensive fabrication process The 3rd generation solar cells consist of any cells that aren’t grouped into the 1st and 2nd generations. Most of the 3 rd generation technologies are not yet commercially implemented, but there is a lot of research going on with a promising future. Dye sensitized solar cell is an organic solar cell of the 3 rd generation 4 .The highest reported efficiency for DSCs with conventional Ru-based dyes is around 11.5% 5,6 . Recently, a Zn-based dye and Co-based electrolyte pair have IJSER