A novel red phosphor, SrIn2O4:Eu3+, Sm3+, is synthesized by a combustion method. The D-5(0) -> F-7(2) transition of Eu3+ is dominantly observed in the photoluminescence spectrum, leading to a red emission of the phosphor. The doped Sm3+ is found to be efficient to sensitize the emission of Eu3+ and be effective to extend and strengthen the absorption of near-UV light with wavelength of 400-405 nm, and the energy transfer from Sm3+ to Eu3+ occurs and is discussed. The effect of the molar concentration of Sm3+ on the emission intensities of the red phosphor SrIn2O4: Eu3+, Sm3+ is investigated. Moreover, the chromaticity coordinates and the emission intensities of SrIn2O4:Eu3+, Sm3+ are compared to those of the conventional red phosphor Y2O2S:Eu3+. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.018112jes] All rights reserved.