I synthesized some cadmium sulphoselenide crystal using hydro-thermal method with the starting materials of Na2S, CdSO4 and Se. Na2S was added into a solution which had CTAB dissolved previously, then Se powder was dissolved in the Na2S solution to form Na2S-Se solution. Then the prepared CdSO4 solution was added into the Na2S-Se solution by drop. The mixture was treated in polytetrafluoroethylene for 8h. CTAB was used as surface modifier, expecting to gain an even distributed spherical cadmium sulphoselenide crystals. But the morphology turned out to be less uniform, and without spherical morphology. Could someone give me some advice to improve the morphology of cadmium sulphoselenide?