Water stable iii-v semiconductor nanocrystal complexes and methods of making same

Abstract

A water-stable semiconductor nanocrystal complex that is stable and has high luminescent quantum yield. The water-stable semiconductor nanocrystal complex has a semiconductor nanocrystal core of a III-V semiconductor nanocrystal material and a water-stabilizing layer. A method of making a water-stable semiconductor nanocrystal complex is also provided.

1 . A water-stable semiconductor nanocrystal complex comprising:
 a semiconductor nanocrystal composition comprising:
 a III-V semiconductor nanocrystal core; and 
 a surface layer comprising molecules having a moiety with an affinity for the semiconductor nanocrystal composition and a moiety with an affinity for a hydrophobic solvent; and 
   a water-stabilizing layer comprising a diblock polymer that surrounds the semiconductor nanocrystal composition to provide a micelle and having a hydrophobic end for interacting with the surface layer and a hydrophilic end, wherein the water-stable semiconductor nanocrystal complex is electronically and chemically stable with a luminescent quantum yield of at least 45% as measured under ambient conditions.   
     
     
         2 . The water-stable semiconductor nanocrystal complex of  claim 1 , wherein the semiconductor nanocrystal composition comprises:
 a metal layer formed on an outer surface of the semiconductor nanocrystal core; and   a shell comprising a semiconductor material overcoating the metal layer.   
     
     
         3 . The water-stable semiconductor nanocrystal complex of  claim 1 , wherein the semiconductor nanocrystal composition comprises:
 a metal layer formed on an outer surface of the semiconductor nanocrystal core; and   a shell comprising an anion layer overcoating the metal layer and a second metal layer overcoating the anion layer.   
     
     
         4 . The water-stable semiconductor nanocrystal complex of  claim 1 , wherein the semiconductor nanocrystal core comprises InP. 
     
     
         5 . The water-stable semiconductor nanocrystal complex of  claim 1 , wherein the semiconductor nanocrystal core is a ternary semiconductor nanocrystal. 
     
     
         6 . The water-stable semiconductor nanocrystal complex of  claim 5 , wherein the ternary semiconductor nanocrystal is InGaP. 
     
     
         7 . The water-stable semiconductor nanocrystal complex of  claim 1 , wherein the luminescent quantum yield is at least 55% as measured under ambient conditions. 
     
     
         8 . The water-stable semiconductor nanocrystal complex of  claim 2 , wherein the semiconductor nanocrystal complex comprises InP, the shell comprises ZnS, and the metal layer comprises Zn. 
     
     
         9 . The water-stable semiconductor nanocrystal complex of  claim 1 , wherein the diblock polymer comprises one selected from poly(acrylic acid-b-methyl methacrylate), poly(methyl methacrylate-b-sodium acrylate), poly(t-butyl methacrylate-b-ethylene oxide), poly(methyl methacrylate-b-sodium methacrylate), poly (methyl methacrylate-b-N-methyl 1-4vinyl pyridinium iodide), poly(methyl methacrylate-b-N,N-dimethyl acrylamide), poly(butadiene-b-methacrylate acid and sodium salt), poly(butadiene(1,2 addition)-b-acrylic acid), poly(butadiene(1,2 addition)-b-sodium acrylate), poly(butadiene(1,4 addition)-b-acrylic acid), poly(butadiene(1,4 addition)-b-sodium acrylate), poly(butadiene(1,4 addition)-b-ethylene oxide), poly(butadiene(1,2 addition)-b-ethylene oxide), poly(styrene-b-acrylic acid), poly(styrene-b-acrylamide), poly(styrene-b-cesium acrylate), poly(styrene-b-sodium acrylate), poly(styrene-b-ethylene oxide), poly(styrene-b-methacrylic acid), poly(styrene-b-sodium methacrylate), and a combination thereof. 
     
     
         10 . The water-stable semiconductor nanocrystal complex of  claim 1 , wherein the hydrophilic end of the water-stabilizing layer comprises a functional group for coupling one or more tertiary molecule. 
     
     
         11 . The water-stable semiconductor nanocrystal complex of  claim 10 , further comprising one or more tertiary molecule coupled to the functional group. 
     
     
         12 . The water-stable semiconductor nanocrystal complex of  claim 11 , wherein the one or more tertiary molecule is a member of a specific binding pair. 
     
     
         13 . The water-stable semiconductor nanocrystal complex of  11 , wherein the member of the specific binding pair is selected from the group consisting of antibody, antigen, hapten, antihapten, biotin, avidin, streptavidin, IgG, protein A, protein G, drug receptor, drug, toxin receptor, toxin, carbohydrate, lectin, peptide receptor, peptide, protein receptor, protein, carbohydrate receptor, carbohydrate, polynucleotide binding protein, polynucleotide, DNA, RNA, aDNA, aRNA, enzyme, substrate. 
     
     
         14 . A substantially monodisperse population of the water-stable semiconductor nanocrystal complexes of  claim 1 . 
     
     
         15 . A method of making a water-stable semiconductor nanocrystal complex comprising:
 synthesizing a semiconductor nanocrystal core comprising a III-V semiconductor nanocrystal material;   forming a surface layer either directly or indirectly on the semiconductor nanocrystal core; and   forming a water-stabilizing layer on the surface layer, the water-stabilizing layer having a hydrophobic end for interacting with the surface layer and a hydrophilic end, wherein the water-stable semiconductor nanocrystal complex is electronically and chemically stable with a luminescent quantum yield of at least 45% as measured under ambient conditions.   
     
     
         16 . The method of  claim 15 , further comprising forming a metal layer on the semiconductor nanocrystal core. 
     
     
         17 . The method of  claim 16 , further comprising overcoating the metal layer with an anion layer. 
     
     
         18 . The method of  claim 17 , further comprising overcoating the anion layer with a second metal layer. 
     
     
         19 . The method of  claim 15 , further comprising overcoating the metal layer with a shell comprising a semiconductor material.