Controllable Synthesis Of Copper-based Chalcogenide Nanomaterials Via A Two-phase Approach

Due to the special photoelectric properties,semiconductor nanocrystal is becoming the mainstream of the next-generation optoelectronic materials,among which chalcogen copper-based semiconductor nanocrystals are widely studied in light emitting devices and solar cells because of their low toxicity,low cost,and good performance.But current popular synthesis methods for nanocrystals are tedious,harsh and environmentally unfriendly,so it is crucial to develop a simple,effective,and green control synthesis approach for nanomaterials for the market.In this study,Cu31S16-CuInS2 nanocrystals have been successfully synthesized using the two-phase synthesis method.On this basis,a series of metal selenide nanocrystals have been synthesized.A carrot-like Cu31S16-CuInS2 semiconductor with heteronanostructures was successfully synthesized by using n-dodecanethiol(DDT)as organic phase and aqueous solution of metal salt as aqueous phase.n-dodecanethiol serves as surface ligand and sulfur source at the same time.The effects of copper-indium ratio,DDT dosage,reaction time,reaction temperature and other conditions on the morphology of Cu31Si6-CuInS2 were investigated.The formation of byproduct,In(OH)3,in the product is suppressed with citric acid as an auxiliary in the synthesis,.and the behavior of cations before participating in the growth of nanocrystals in the process of the synthesis of nanocrystals by the two-phase interface method was discussed.The mechanism of inhibiting ln(OH)3 of citric acid is and the crystal growth process in the two-phase synthesis method are elucidated.Metal selenide semiconductor nanocrystals were successfully synthesized by using the aqueous solution of metal salt as a cation precursor.The selenium precursor was prepared by dissolve selenium powder in 1-Octadecene(ODE)at high temperatures.In the process of synthesizing semiconductor nanocrystals of copper-selenium compounds,the effect of the ratio of precursors,the type of surface ligands,and reaction time on the morphology of the products were investigated.In addition,we have developed a method for dissolving selenium powder at room temperature.Using this method,we have successfully prepared nanocrystals of copper-selenium compounds with uniform morphology and good dispersibility.On this basis,we changed the types of metal salts and successfully synthesized other metal selenide semiconductor nanocrystals.The two-phase method was successfully applied to the synthesis of selenide nanocrystals by the method of using octadecene to dissolve selenium powder.It is verified through experiments that this method can synthesize various selenide nanocrystals and synthesize multiple metal selenides.It greatly expands the range of materials that can be synthesized.