Continuous Synthesis Of High Quantum Yield InP/ZnS Nanocrystals

Abstract

The invention relates to a continuous-flow synthesis process for the preparation of high quality indium phosphide/zinc sulfide core/shell semiconduting nanocrystals in particular quantum dots (QD) conducted in a micro-reaction system comprising at least one mixing chamber connected to one reaction chamber.

1 . (canceled) Continuous-flow method for the preparation of InP/ZnS nanoparticles conducted in a micro-reaction system comprising at least one mixing chamber connected to one reaction chamber and comprising the following steps:
 a. Preparing an indium precursor solution by mixing an indium salt, a fatty protic alkylamine, a fatty alkylacid and zinc carboxylate with an inert solvent optionally heating up to 50-200° C. to get a clear solution under water and oxygen free atmosphere,   b. Preparing a phosphine precursor solution comprising tris(trimethylsilyl) phosphine in the inert solvent under water and oxygen free atmosphere,   c. Injecting the indium precursor solution in excess to the phosphine precursor solution into the mixing chamber to obtain a reaction mixture, wherein the mixing chamber is a magnetic mixing micro-chamber, preferably at a flow rate from 0.1 ml/min to 10 ml/min,   d. Forwarding and heating the reaction mixture at a temperature from 160 to 320° C., within the reaction chamber until InP core suspension is obtained,   e. Forwarding the core suspension into a mixing chamber and injecting a shell precursor solution comprising a Zn source and a S source to the core suspension and preferably capping ligands into the mixing chamber,   f. Forwarding and heating the suspension at a temperature from 160 to 320° C., preferred 200 to 280° C. for shell preparation within the reaction chamber,   g. Cooling.   
     
     
         2 . (canceled) Method according to  claim 1  wherein Zn source and S source is a single source. 
     
     
         3 . (canceled) InP/ZnS nanoparticle obtainable by the method of  claims 1  to  2 . 
     
     
         4 . (canceled) Formulation comprising the nanoparticle of  claim 3 . 
     
     
         5 . (canceled) Device comprising the nanoparticle of  claim 3 . 
     
     
         6 . A InP/ZnS nanoparticle obtainable by a continuous-flow method for preparing InP/ZnS nanoparticles conducted in a micro-reaction system comprising at least one mixing chamber connected to one reaction chamber, said method comprising:
 preparing an indium precursor solution by mixing an indium salt, a fatty protic alkylamine, a fatty alkylacid, and zinc carboxylate with an inert solvent and heating up to 50-200° C. to get a clear solution under water and oxygen free atmosphere;   preparing a phosphine precursor solution comprising tris(trimethylsilyl) phosphine in the inert solvent under water and oxygen free atmosphere;   injecting the indium precursor solution in excess to the phosphine precursor solution into the mixing chamber to obtain a reaction mixture, wherein the mixing chamber is a magnetic mixing micro-chamber with a volume in the range of 10 mm 3  to 10,000 mm 3 , and wherein the injecting is at a flow rate from 0.1 ml/min to 10 ml/min ;   forwarding and heating the reaction mixture at a temperature from 160 to 320° C., within the reaction chamber until InP core suspension is obtained;   forwarding the core suspension into a mixing chamber and injecting a shell precursor solution comprising a Zn source and a S source to the core suspension and capping ligands into the mixing chamber;   forwarding and heating the suspension at a temperature from 160 to 320° C. for shell preparation within the reaction chamber; and cooling.   
     
     
         7 . A formulation comprising the nanoparticle of  claim 6 . 
     
     
         8 . A device comprising the nanoparticle of  claim 6 .