Formation of CrSi2 film and measurement of optical band gap energy

The surface morphology and natural composition of the movies were analyzed for different temperature conditions. Thin films of CrSi2/Si(111) were formed on polished substrates heated to 480 K using a special heater in a vacuum of 1.2•10-4 mbar by the solid-phase ion-plasma method. During the experiment, the substrates were mounted on a rotating carousel holder at a distance of 150 mm from the surface of the magnetron target. The magnetron power supply current is 716 mA, power 263 W, voltage 320 V. Thin films of CrSi2 are formed from a CrSi2 target with a purity of 99.5% by the solid-phase ion-plasma method. The measurement results show that the elemental stoichiometric composition of thin CrSi2 films grown by the solid-phase ion plasma method is Si/Cr = 33.6/62.32, which confirms the formation of chromium disilicide. Using optical spectroscopy methods, the widths of indirect and direct band gaps of amorphous and nanostructured thin films of chromium disilicide grown by the ion-plasma method in high vacuum were determined, and a comparative analysis was carried out with theoretically determined values based on the theories of Townes, Kumar, and Kubelka-Munk. The results showed that the band gap for Si(111) and CrSi2 polycrystalline films is 1.1512 eV and 0.3543 eV. Tauc plots show that CrSi2 thin films have an indirect band gap (energy of indirect allowed optical transitions): Eoptg.ind=0,064 eV and Eoptg.ind =0,068 eV, respectively, and direct band gap (energy of direct allowed optical transitions) Eoptg.ind =0,354 eV and Eoptg.ind =0,368 eV. This research serves to enhance scientific research on band gap determination of silicide thin films.