Preparation and Photoluminescence Properties of Eu3+-Doped Al2O3 Films on Silicon Substrates by the Sol-gel Method

Eu3+-doped Al2O3 films on silicon substrates were prepared by the sol-gel method. The Eu3+-doped Al2O3 films were characterized by differential thermal analysis/thermogravimetric analysis, X-ray diffraction, scanning electron microscope, atomic force microscope and photoluminescence spectra as well. The photoluminescence mechanism of Eu3+-doped Al2O3 films was analyzed. The effects of heat-treating temperature and Eu3+ ion concentration on the luminescence property of Al2O3:Eu3+ films were discussed. The results show that the prepared Al2O3:Eu3+ films have high luminescence intensity, the optimum excitation wavelength is 265 nm, the optimum concentration of Eu(3+)dopant is 10 mol%, and the main emission is at 617 nm under excitation of 265 nm. The prepared Al2O3:Eu3+ film has a dense, smooth and crack-free surface texture with a roughness less than 1.4 nm. It is concluded that the film is good enough for fabrication and application of silicon based photoelectronic devices.