Power　conversion　efficiency　of　dye　sensitized　solar　cell　(DSSC)　is　closely　related　to　photo-anode＇s　structure.　It　has　been　believed　that　titanium　dioxide　(TiO2)　nanotube　array　thin　film　is　one　of　the　best　photo-anode　candidates　for　DSSC.　However,　the　insufficient　internal　surface　area　and　wide　band　gap　of　pure　anatase　limit　their　power　conversion　efficiency.　Here　we　report　a　novel　TiO2　nanotube　array　film　synthesized　by　anodization　followed　by　surface　modification　with　nitrogen　(N)　doped　TiO2　nanoparticles　using　a　solvothermal　method.　The　incorporation　of　N　doped　TiO2　nanoparticles　along　the　wall　of　TiO2　nanotubes　not　only　provides　a　large　surface　area　for　dye　loading,　but　also　increases　the　conductivity　of　the　electrode,　generating　an　overall　power　conversion　efficiency　of　2.53%,　which　is　68%　higher　than　that　with　pure　TiO2　nanotube　array　(with　the　length　of　1.8　mu　m)　photoanode.　When　the　length　of　TiO2　nanotube　increased　to　4.1　mu　m,　the　overall　power　conversion　efficiency　can　be　improved　to　be　4.9%,　which　is　higher　than　the　previous　reported　results　using　the　same　length　of　nanotube.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.