Bhim P. Kafle, Babu R. Pokhrel, Rajendra Gyawali, Ananda. Kafle, Tirtha M. Shrestha, Ramita Shrestha and Ravi. M. Adhikari
Optical transmittance of various natural organic- and synthetic (commercial)- dyes has been measured in the wavelength range of 310-900 nm. The pure natural dye from raw samples of either flower or root of plants were extracted and dried following standard method. Then the powder of both natural and synthetic dyes were dissolved in ethanol for transmittance measurements by UV-Visible spectrometric technique. In the visible region of electromagnetic radiation, all the natural dye samples show poor absorbance, except Maharanga bicolor. While the synthetic dyes, specifically, Green-VS, Patent-Blue and Black-ADLI show strong absorbance over the wide range in the visible spectrum, demonstrating the prospect of utilizing in the fabrication of dye sensitized solar cells. Uniquely, a natural dye extracted from root of herb Maharanga bicolor shows characteristic peak at around 500 nm, associated with rovibronic transitions
