Cu2ZnSnS4　thin　films　with　different　Cd　compositions　were　prepared　using　sputtering-sulfuration　method.　The　best　device　with　efficiency　as　high　as　10.65%　was　achieved.　The　scanning　electron　microscope,　temperature　dependent　photoluminescence,　excitation　power　dependent　photoluminescence　were　employed　to　character　the　materials　and　the　capacitance-voltage　and　current-voltage　characteristics　of　the　solar　cells　were　studied.　It　is　revealed　that　the　photoluminescence　of　Cd　doped　Cu2ZnSnS4　is　dominated　by　donor-acceptor　pairs,　with　carriers　showing　strong　localization.　Cd　incorporation　is　found　to　be　beneficial　in　removing　deep　defects　and　reduce　the　energy　shift　between　the　emission　peak　and　absorption　edge,　resulting　in　the　reduction　of　the　open　circuit　voltage　loss　of　the　solar　cell　device.　These　findings　are　helpful　to　make　further　improvement　in　device　efficiency.　©　2017,　Science　Press.　All　right　reserved.