Author : F. Hassan, Adnan
journal of kerbala university,
Volume 12, Issue 2, Pages 236-244
In this study , we had been three organic pigments extraction from Vinca flowers ,which are they have five color (yellow , red, white ,pink and purple) in the laboratory at room temperature. So we measurement the concentration of solvent for each the three pigments extraction from vinca pink , yellow and purple, considering the concentration for each pigment is constant .
The optical characteristics had been studied like (absorption, transmittance, reflectance ,Fluorescence and energy gap ). Also the optical constant were calculated including (absorption coefficient and extinction coefficient ) for three pigments and shown that the value of absorption coefficient increases when the Photon Energy increases, with constant the concentration ,but the value of extinction coefficient is decreases with increases wavelength.
Absorption and fluorescence for the three extraction pigments is a good, they have ability to absorbed a high quantity from the sun light.
The results also shown that the values of energy gap for the three pigments are( 2.5 - 2.1 ) eV, which is within the limits work of the solar cell energy gap (photon energy was largest then or equal energy gap).