Cuub>2ub>ZnSn(Sub>1鈭?em>xub>Seub>xub>)ub>4ub> thin films have been synthesized using a simple annealing process of vacuum deposited precursors under selenium atmosphere. Scanning electron microscopy as well as Raman spectroscopy exhibit high quality layers without minors phases. Energy dispersive spectroscopy in a transmission electron microscope however reveals the presence of ZnSub>1鈭?em>xub>Seub>xub> that is not easily distinguishable with other techniques of detection. Thin film Cuub>2ub>ZnSn(Sub>1鈭?em>xub>Seub>xub>)ub>4ub> based solar cells have been completed using a classical Cuub>2ub>ZnSn(Sub>1鈭?em>xub>Seub>xub>)ub>4ub>/CdS/ZnO structure. Power conversion efficiency of 6.0%has been reached.