Optical properties of rhodamine B dye mixed with polyvinylpyrrolidone (PVP )‎ as a matrix

Abstract EN

In the present work, the spin casting method has been utilized for preparing different concentrations of Rhodamine B (Rh B) (5%,10% and 15%) mixed with a transparent polymer Polyvinylpyrrolidone (PVP) as a matrix.

The spectral characteristics of the prepared samples are studied by absorption, transmission, reflection (the wavelength region from 300 nm to 900 nm) and fluorescence spectroscopy (the wavelength region from 550 nm to 800 nm).

The calculated Stokes shift between the absorption and emission of Rh.B reflects the displacement in potential surface between the ground and the excited states.

The analysis of the spectral behavior of the absorption coefficient in the absorption region reveals an direct allowed transition with a band gap of 2.07 eV .

The values of some important parameters (refractive index n and extinction coefficient K ) of polymer thin film are determined from these spectra.