The Er3+-doped Al2O3 films with y3+ codoping were prepared on SiO2/Si(100) substrates by a non-aqueous sol-gel process and a dipping method,from 0.1 mol% Er3+-doped sols with Y3+ codoping concentration of 1-10 mol%.The effects of Y3+ codoping on the structure and the photoluminescence (PL) properties of the films were investigated.X-ray diffraction (XRD) analysis showed that both the non-codoped and the codoped films were of γ phase structure.Fourier transform infrared spectroscopy (FT-IR) measurement confirmed the Al-O stretching bands and the O-H stretching band for all the films,where no obvious variations of their positions and relative intensities were observed after y3+ codoping.The PL spectra with the strongest peak at 1.534 μm were obtained for both the non-codoped and the codoped films.The PL intensity increased progressively with increasing the Y3+ codoping concentration,and 10 mol% Y3+ codoping intensified the PL intensity by 20 times,compared with that of the non-codoped film.The enhancement in PL intensity is due to the improved dispersion of Er3+ in Al2O3 matrix by the Y3+ codoping.