TiO2-Y2O3　core　shell　nanoparticles　for　dye-sensitized　solar　cells　(DSSCs)　have　been　fabricated　by　a　solvothermal　technique.　The　heterostructure　of　TiO2　nanoparticles　coated　with　porous　Y2O3　is　confirmed　with　transmission　electron　microscopy.　The　bonding　of　the　Y2O3　coating　on　the　TiO2　surface　is　quantitatively　analyzed　in　terms　of　the　Lifshitz-van　der　Waals　and　electrostatic　contributions　to　the　surface　free　energy　of　the　particles.　TiO2　and　Y2O3　constitute　a　core-shell　heterojunction　because　the　Fermi　levels　merge;　this　increases　the　open-circuit　voltage.　Higher　recombination　resistances　are　obtained　in　DSSCs　with　porous　Y2O3-coated　TiO2　compared　with　those　in　the　reference　cells,　indicating　＂backscattering＂　inhibition　of　the　porous　Y2O3　barrier　on　TiO2　nanoparticles.　Moreover,　smaller　transport　resistances　and　longer　electron　lifetimes　are　achieved　in　DSSCs　with　TiO2-Y2O3　core　shell　nanoparticles.　Compared　with　a　reference　cell,　the　V-OC　of　a　DSSC　with　a　partial　Y2O3　coating　on　the　surface　of　the　TiO2　nanoparticles　improves　from　683　to　738　mV　and　the　J(sc)　from　14.15　to　15.35　mA　center　dot　cm(-2),　whereas　the　conversion　efficiency　increases　by　15.2%.