Thin Films of Azo Dye (1-Phenylazo-2-Naphthol) have been prepared by thermal evaporation technique onto quartz substrates held at about 300 K during the deposition process with different thicknesses range 625–880 nm. X-ray diffraction and the differential thermal analysis showed that the Azo Dye sample is crystalline nature and thermal stable in temperature range from room temperature to 100  $^{\circ}$ C. The optical constants (the refractive index n, the absorption index k and the absorption coefficient α) were calculated for Azo Dye (1-Phenylazo-2-Naphthol) thin films by using spectrophotometer measurements of the transmittance and reflectance at normal incidence in the spectral range 400–2200 nm. The obtained values of both n and k were found to be independent of the film thicknesses. The refractive index has anomalous behavior in the wavelength range 400–1000 nm besides a high energy transition at 2.385 eV. The optical parameters (the dispersion energy E d , the oscillation energy E o , the room temperature optical dielectric constant $\varepsilon_{l}$ , the lattice dielectric constant $\varepsilon_{L}$ , the high frequency dielectric constant $\varepsilon_{\infty}$ and the ratio of carrier concentration to the effective mass $N/m^{\ast}$ ) were calculated. The allowed optical transition responsible for optical absorption was found to be direct transition with optical energy gap of 1.5 eV for Azo Dye sample. The band tail obeys Urbach's empirical relation. 

Electrical conductivity was performed on amorphous thin films of Ge1–x Se2Pbx (with x = 0, 0.2, 0.4, 0.6 and 0.8) as a function of temperature in the range 300–450 K. The experimental results indicate that the conduction is through thermally activated process having two conduction mechanisms. In the first region at high-temperatures range, the values of $\sigma _{o}$ suggest that the dominant conduction of charge carriers changes from the extended states to the localized states in the band tails at composition x = 0.8. The experimental results have also been analyzed using Meyer-Neldel Rule. The other one appears in the low temperatures region and the conductivity has been analyzed using Mott's variable range hopping conduction. Mott's parameters were calculated for Ge1–x Se2Pbx films.