Preparation and Photoluminescence Properties of Tb~(3+)-doped Al_2O_3 Films on Silicon Substrates
硅衬底Al_2O_3∶Tb~(3+)薄膜的制备及其发光性能

Tb~(3+)-doped Al_2O_3 films on silicon substrates were prepared by the sol-gel method. The Tb~(3+)-doped Al_2O_3 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 Tb~(3+)-doped Al_2O_3 films was analyzed. The effects of heat-treatment temperature and Tb3+ ion concentration on the luminescence property of Tb~(3+)∶Al_2O_3 films were discussed. The results show that the prepared Al_2O_3∶Tb~(3+) film has high luminescence intensity, the optimum excitation wavelength is 240nm, the optimum concentration of Tb~(3+) dopant is 5mol%, and the main emission is at 544nm under excitation at 240nm. And the prepared Al_2O_3∶Tb~(3+) film has a dense, smooth and crack-free surface texture with a roughness of less than 1.3nm. It is suggested that the film is good enough for fabrication and application of silicon based photoelectronic devices.