Structural, optical and electrical, properties of As-Se-Tl films

Bulk alloys of A¿s-Se-Tl were synthesized by weighting out ¿suitable proportions of the required compositions with purity ¿¿5N. Melting them up to 875 C for 16 hours followed by rapid ¿quenching in ice water.¿Thermal evaporation technique was used ¿to prepare A¿s-Se-Tl films on glass substrates. The produced ¿films have 200 nm thickness. X-ray diffraction and differential ¿scanning calorimetry were used to investigate the film structural ¿properties. The nature of the produced alloys, ¿Glass transition, ¿crystallization temperature and melting point as well as the ¿permittivity of the as-deposited and annealed films up to 373 K ¿were studied as function of Tl-content. Optical constants like ¿dispersion energy, high frequency dielectric constant, lattice ¿dielectric constant, and the oscillator energy were determined. ¿Composition effect on the dc electrical properties was ¿investigated in the temperature range (175-375)K. Hopping ¿conduction ¿dominates at low temperature region (173-300) K. ¿At the high temperature region (300-373) K, band conduction ¿occurs. Seebeck coefficient, a.c conductivity¿ and related ¿constants were determined.¿