Studies on Optoelectronic Properties of DC Reactive Magnetron Sputtered Chromium Doped CdO Thin Films

摘要

Cr doped CdO thin films were deposited on glass substrates by DC reactive magnetron sputtering method and subsequently annealed from 200 ?C to 500 ?C. X-ray diffraction analysis showed that the films exhibit (1 1 1) preferred orientation. The optical transmittance of the films increases from 64% to 88% with increasing annealing temperature. The optical band gap values were found to be decreased from 2.77 to 2.65 eV with the increase of annealing temperature. The decrease in optical band gap energy with increasing annealing temperature can be attributed to improvement in the crystallinity of the films and may also be due to quantum confinement effect. A minimum resistivity of 2.23 x 10~(-4) Ω.cm and sheet resistance of 6.3 Ω/sq is obtained for Cr doped CdO film annealed at 500 ?C.