A　series　of　near-infrared　(NIR)　down-conversion　phosphors　of　La3Ga5SiO14　(LGS):Ce3+/Yb3+　were　synthesized　via　high-temperature　solid-state　reaction.　Under　excitation　at　345　nm,　the　phosphors　show　strong　NIR　emission　around　978　nm,　which　matches　well　with　the　optimal　spectral　response　of　crystalline　silicon　(c-Si)　solar　cells.　The　emission　spectra　and　decay　curves　were　used　to　demonstrate　the　energy　transfer　from　Ce3+　to　Yb3+.　The　energy　transfer　mechanism　was　discussed　in　detail,　indicating　that　the　energy　transfer　from　Ce3+　to　Yb3+　is　dominated　by　a　single　photon　process,　and　the　energy　transfer　efficiency　is　up　to　51%.　In　addition,　La3Ga5-zAlzSiO(14)　(z　=　0,　1,　2,　3):Ce3+/Yb3+　were　also　synthesized.　The　NIR　emission　intensity　of　La(3)Ga(2)Al(3)SiO(14:)1%Ce3+/5%Yb3+　is　4.6　times　that　of　LGS:1%Ce3+/5%Yb3+,　and　the　thermal　relaxation　was　used　to　explain　this　phenomenon.　The　results　show　that　La3Ga5-zAlzSiO(14)　(z　=　0,　1,　2,　3):1%Ce3+/5%Yb3+　phosphors　have　the　potential　to　increase　the　conversion　efficiency　of　c-Si　solar　cells.