Red emission of Eu3+ ions has been observed in the Y2O3:Eu3+/Zn1-xCdxO film structure by radiative energy transfer from Zn1-xCdxO films underneath to Y2O3:Eu3+ phosphor films deposited on top. The peak wavelength of the Zn1-xCdxO films has been tuned from 381 to 394 nm by increasing the concentration of Cd dopants. When the peak wavelength of Zn1-xCdxO films shifts toward the absorption wavelength of Eu3+ ions at 394 nm, this results in a larger spectral overlap and hence a more efficient radiative energy transfer from the Zn1-xCdxO films to the Y2O3:Eu3+ phosphor films. As a result, the photoluminescent intensity of the Eu3+ ion centers at about 611 nm increases.