Studying the optical conductivity of plastic polystyrene thin film prepared by spin coating technique

In this research we studied the relationship between the optical conductivity Ϭop and photon energy (hν), the absorbance coefficient (α), transmittance (T), the refractive index (no), and the real part and imaginary part of dielectric constant (εr, εi), the spinning velocity of deposition device (v), for a specific wave length (600nm), for a pure thin film prepared from an organic polymer material, Polystyrene (PS), by spin coating technique, on three velocities ( 1000-2000-3000)RPM, in room temperature and 1atm. It was shown that the PS film is a transmittive film with a transmittance values reach ( 85 – 90 )% in the infrared region, and the optical conductivity Ϭop increased with the photon energy, and for the velocity 1000RPM it took the highest value ( 1.67 X 1014 )1/sec, at the photon energy (hν =3.1 ev) and the wave length ( λ= 400nm ), which means that the optical conductivity Ϭop is active in the visible region, and also it decreases with the spinning velocity. The values of energy gap for allowed direct transitions were (2.5ev), (2.4ev), (2.3ev) for the films prepared on 1000RPM, 2000RPM, 3000RPM, and for the forbidden direct transitions were (2.3ev), (2.2ev), (2.1ev) respectively . The biggest value of Urbach energy Eu was (163mev) on the velocity 1000RPM and the lowest value was (109mev) on the velocity 3000RPM.

Preparing pure thin films from poly vinyl chloride and studying the effect of the rotating velocity on the optical constants

In this research we have prepared thin films from poly vinyl chloride (PVC) by spin coating technique in three velocities (1000,2000,3000)RPM on glass substrate (Micro scope cover glass), at room temperature. The absorbance A, and transmittance T for the films were studied in the visible and ultra-violet region (UV-VIS). In addition,we have calculated the absorbance coefficient α, skin depth δ, refractive index no, dielectric constant ε (the real part and the imaginary part), also we have calculated the energy band gap of allowed and forbidden direct transitions. The films showed high transmittance (80-90)%, in the infrared region as a function of the spinning velocity and took the maximum value 80% for the velocity 1000RPM, and 90% for the velocity 3000RPM, and the refractive index was decreased with the velocity increase, we found it between3.67 and 4.56 for the velocities 3000RPM and 1000RPM respectively. Whereas the skin depth δ decreased with the increasing of velocity, the minimum value was 0.0000531cm for the velocity 3000RPM and the maximum value was almost 0.00023cm for the velocity 1000RPM.