The　performance　of　dye-sensitized　ZnO　solar　cells　was　improved　by　a　facile　surface-treatment　approach　through　chemical-bath　deposition.　After　the　surface　treatment,　the　quantum　dots　of　Zn　2SnO　4　were　deposited　onto　ZnO　nanoparticles　accompanied　by　the　aggregations　of　Zn　2SnO　4　nanoparticles.　The　ZnO　film　displayed　a　better　resistance　to　acidic　dye　solution　on　account　of　the　deposited　Zn　2SnO　4　nanoparticles.　Meanwhile,　the　open-circuit　photovoltage　was　greatly　enhanced,　which　can　be　ascribed　to　the　increased　conduction-band　edge　of　ZnO　and　inhibited　interfacial　charge　recombination.　Although　the　deposition　of　Zn　2SnO　4　decreased　the　adsorption　amounts　of　N719　dye,　the　aggregates　of　Zn　2SnO　4　with　a　size　of　350-450　nm　acted　as　the　effective　light-scattering　layer,　thereby　resulting　in　an　improved　short-circuit　photocurrent.　By　co-sensitizing　10　μm-thick　ZnO　film　with　N719　and　D131　dyes,　a　top　efficiency　of　4.38　%　was　achieved　under　the　illumination　of　one　sun　(AM　1.5,　100　mW　cm　-2).Copyright　©　2012　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim.