Preparation and Photoluminescence Properties of Tb~(3+)-doped Al_2O_3 Films on Silicon Substrates

Tb3+-doped Al2O3 films on silicon substrates were prepared by the sol-gel method.The Tb3+-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 Tb3+-doped Al2O3 films was analyzed.The effects of heat-treatment temperature and Tb3+ ion concentration on the luminescence property of Tb3+∶Al2O3 films were discussed.The results show that the prepared Al2O3∶Tb3+ film has high luminescence intensity,the optimum excitation wavelength is 240nm,the optimum concentration of Tb3+ dopant is 5mol%,and the main emission is at 544nm under excitation at 240nm.And the prepared Al2O3∶Tb3+ 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.