Studies on structural and optical properties of DC reactive magnetron sputtered Cr doped CdO thin films

摘要

Cr doped CdO thin films were deposited on mica substrates by D C reactive magnetron sputtering method by varying oxygen flow rates from 1 to 4 sccm. X -ray diffraction peaks indicates that the films were polycrystalline in nature with cubic structure. The intensity of the (2 0 0) peaks increased with the increase of oxygen flow rates. The resistivity increases from 2.12 x 10 -4 to 5.71 x 10 -4 Ω.cm with the increase of oxygen flow rate from 1 to 4 sccm. The carrier concentration of Cr doped CdO thin films decreases from 1.04 x 10 20 to 0.68 x 10 20 cm -3 with the increase of oxygen flow rate from 1 to 4 sccm. The optical transmittance of the thin films increases with the increase of oxygen flo w rate. The optical band gap energy is varied from 2.57 to 2.69 eV with the increase of oxygen flow rate. The optical constants such as absorption coefficient (α), extinction coefficient (k) and refractive index (n) were also determined from the optical transmission data.