Growth of chromium-doped alumina thin films by metal-organic chemical vapour deposition

Abstract

Amorphous thin films of chromium-doped alumina were grown from Al(OiPr)3 (iPr, Isopropyl) and Cr(CO)6 on silicon and quartz substrates by chemical vapour deposition at 673 K. The films were annealed at 1223 and 1473 K to form chromium-doped γ-Al2O3 and γ-Al2O3respectively. The lattice constant a of the γ-Al2O3thin films enlarged with increasing Cr Concentration. The lattice constant a (=b) of the α-Al2O3 thin films increased while the lattice constant c decreased with increasing Cr concentration. UV-visible spectra of the annealed films showed maximum absorptions near 380, 500 and 690 nm.