Hybrid nanostructured materials based in II-VI semiconductors

Abstract

Hybrid crystalline organic-inorganic quantum confined systems are disclosed, which contain alternating layers of a bifunctional organic ligand and a II-VI semiconducting chalcogenide, wherein the semiconducting chalcogenide layers contain chalcogenides have the formula MQ, in which M is independently selected from II-VI semiconductor cationic species and Q is independently selected from S, Se and Te; and the bifunctional organic ligands of each organic ligand layer are bonded by a first functional group to an element M of an adjacent II-VI semiconducting chalcogenide layer and by a second functional group to an element M from the adjacent opposing II-VI semiconducting chalcogenide layer, so that the adjacent opposing II-VI semiconducting chalcogenide layers are linked by the bifunctional organic ligands of the organic ligand layers. Optical absorption experiments show that these systems produce a significant blue shift in their optical absorption edges, 1.2-1.5 eV, compared to a shift of 1.0 electron volt by the best grown II-VI or II-V semiconducting quantum colloidal dots. In addition, the II-VI confined layers in these systems possess a perfectly periodic arrangement.

1. A hybrid crystalline organic-inorganic quantum confined system comprising alternating layers of bifunctional organic ligands and II-VI semiconducting chalcogenides, wherein:
 the semiconducting chalcogenide layer comprises II-VI chalcogenides having the formula MQ, in which each M is independently selected from the group consisting of II-VI semiconductor cationic species, and each Q is independently selected from the group consisting of S, Se and Te; and  
 said bifunctional organic ligands of each organic ligand layer are bonded by a first functional group to an element M of an adjacent II-VI semiconducting chalcogenide layer and by a second functional group to an element M from the adjacent opposing II-VI semiconducting chalcogenide layer, so that said adjacent opposing I-VI  II- VI  semiconducting chalcogenide layers are linked by said bifunctional organic ligands of said organic ligand layers.  
 
     
     
       2. The quantum confined system of  claim 1 , wherein M of said hybrid compound  is Zn or Cd. 
     
     
       3. The quantum confined system of  claim 1 , wherein Q of said hybrid compound  is Se or Te. 
     
     
       4. The quantum confined system of  claim 1 , wherein the bifunctional organic ligand of said of hybrid compound  is an organic diamine having the formula R—(NH 2 ) 2 , and wherein R is a C 2 -C 6  straight-chained or branched, substituted or unsubstituted, saturated or unsaturated, aliphatic or cycloaliphatic  hydrocarbon. 
     
     
       5. The quantum confined system of  claim 4 , wherein said diamine of said hybrid compound  is ethylenediamine or 1,3-propanediamine. 
     
     
       6. The quantum confined system of  claim 1 , further comprising additional II-VI semiconducting chalcogenide layers between adjacent opposing bifunctional organic ligand layers. 
     
     
       7. The semiconductor device comprising the quantum confined system of  claim 1 . 
     
     
       8. A method for the preparation of a crystalline organic-inorganic hybrid quantum confined system comprising plural alternating layers of a bifunctional organic ligand and II-VI semiconducting chalcogenides, said method comprising:
 the step of heating a mixture comprising; :
 (a) a salt of one or more II-VI semiconductor cationic species;  
 (b) one or more chalcogens selected from the group consisting of S, Se and Te; and  
 (c) a bifunctional organic compound capable of forming covalent or coordinate bond  bonds with said II-VI semiconductor cationic species;  
 
 at a temperature effective to form said hybrid compound  system, until said hybrid compound  system is formed.  
 
     
     
       9. A  The method according to  of  claim 8 , wherein said salt is a salt of Zn and/or Cd. 
     
     
       10. The method of  claim 8 , wherein said one or more chalcogen  chalcogens are selected from the group consisting of S, Se or Te. 
     
     
       11. The method of  claim 8 , wherein said bifunctional organic compound is an organic diamine having the formula R—(NH 2 ) 2 , and wherein R is a C 2 -C 6  straight-chained or branched, substituted or unsubstituted, saturated or unsaturated, aliphatic or cycloaliphatic  hydrocarbon. 
     
     
       12. The method of  claim 11 , wherein said organic diamine is ethylenediamine or 1,3-propanediamine. 
     
     
       13. A quantum confined system comprising a plurality of alternating layers, wherein the layers alternate between a bifunctional organic ligand layer and a II- VI semiconductor layer, wherein the bifunctional organic ligand layers include organic diamines having the formula R— ( NH   2 ) 2   , wherein R is a C   2 - C   6    straight - chained or branched, substituted or unsubstituted, saturated or unsaturated, aliphatic hydrocarbon.   
     
     
       14. The system of  claim 13 , wherein each bifunctional organic ligand layer includes bifunctional organic ligands that are bonded by  1 )  a first functional group to a metal element of an adjacent II - VI semiconductor layer and  2   )  a second functional group to a metal element of another adjacent II - VI semiconductor layer.   
     
     
       15. The system of  claim 13 , wherein said quantum confined system functions as a quantum well, and wherein said system is a crystalline organic- inorganic hybrid structure.   
     
     
       16. A quantum confined system comprising a plurality of alternating layers, wherein the layers alternate between a bifunctional organic ligand layer and a II- VI semiconductor layer, wherein the II - VI semiconductor layer includes II - VI compounds having the formula MQ, in which each M is independently selected from the group consisting of the II - VI semiconductor cationic species, and each Q is independently selected from the group consisting of S, Se and Te, and wherein organic ligands within the bifunctional organic ligand layers have functional groups that are chemically bonded to adjacent II - VI semiconductor layers.   
     
     
       17. The system of  claim 16 , wherein each bifunctional organic ligand layer includes bifunctional organic ligands that are bonded by  1 )  a first functional group to a metal element of an adjacent II - VI semiconductor layer and  2   )  a second functional group to a metal element of another adjacent II - VI semiconductor layer.   
     
     
       18. The system of  claim 16 , wherein said quantum confined system functions as a quantum well, and wherein said system is a crystalline organic- inorganic hybrid structure.   
     
     
       19. The system of  claim 16 , wherein each M is independently selected from the group consisting of Zn, Cd, Hg, and Mn. 
     
     
       20. A method comprising:
   heating a mixture to a temperature effective to form a crystalline organic - inorganic hybrid structure, wherein the mixture includes at least one group II material, at least one group VI material, and a bifunctional organic compound, wherein the bifunctional organic compound is capable of forming covalent or coordinate bonds with II - VI semiconductor cationic species; and        maintaining the mixture at the temperature until the hybrid structure is formed, wherein the hybrid structure is defined by alternating layers of a first layer of the bifunctional organic compound and a second layer of II - VI semiconductor compounds.     
     
     
       21. The method of  claim 20 , further comprising washing the hybrid structure free of starting materials and impurities with a solvent, and drying the hybrid structure with an anhydrous solvent. 
     
     
       22. The method of  claim 20 , wherein said mixture includes a II- VI semiconductor component provided as a precursor and reacted directly with the bifunctional organic compounds.   
     
     
       23. The method of  claim 20 , wherein said heating the mixture is performed in a closed or sealed vessel at elevated pressure. 
     
     
       24. A crystalline organic- inorganic hybrid compound comprising a II - VI semiconductor layer, a bifunctional organic ligand layer, and an additional II - VI semiconductor layer, wherein said bifunctional organic ligand layer includes bifunctional organic ligands that are organic diamines having the formula R— ( NH   2 ) 2   , wherein R is a C   2 - C   6    straight - chained or branched, substituted or unsubstituted, saturated or unsaturated, aliphatic hydrocarbon.   
     
     
       25. The compound of  claim 24 , wherein said compound includes a total number of layers, wherein said total number is greater than three, wherein said total number of layers alternates between said II- VI semiconductor layer and said bifunctional organic ligand layer.   
     
     
       26. The compound of  claim 24 , wherein said bifunctional organic ligand layer includes bifunctional organic ligands that are bonded by  1 )  a first functional group to a metal element of said II - VI semiconductor layer and  2   )  a second functional group to a metal element of said additional II - VI semiconductor layer.   
     
     
       27. A crystalline organic- inorganic hybrid compound comprising a II - VI semiconductor layer, a bifunctional organic ligand layer, and an additional II - VI semiconductor layer, wherein the II - VI semiconductor layer includes II - VI compounds having the formula MQ, in which each M is independently selected from the group consisting of the II - VI semiconductor cationic species, and each Q is independently selected from the group consisting of S, Se and Te, and wherein organic ligands within the bifunctional organic ligand layers have functional groups that are chemically bonded to adjacent II - VI semiconductor layers.   
     
     
       28. The compound of  claim 27 , wherein said compound includes a total number of layers, wherein said total number is greater than three, and wherein said layers in said compound alternate between said II- VI semiconductor layer and said bifunctional organic ligand layer.   
     
     
       29. The compound of  claim 27 , wherein said bifunctional organic ligand layer includes bifunctional organic ligands that are bonded by  1 )  a first functional group to a metal element of said II - VI semiconductor layer and  2   )  a second functional group to a metal element of said additional II - VI semiconductor layer.   
     
     
       30. The compound of  claim 27 , wherein each M is independently selected from a group consisting of Zn, Cd, Hg, and Mn. 
     
     
       31. A method comprising:
   heating a mixture to a temperature effective to form a crystalline organic - inorganic hybrid structure comprising three or more alternating layers, wherein the layers alternate between a bifunctional organic ligand layer and a II - VI semiconductor layer, wherein the bifunctional organic ligand layers include organic diamines having the formula R— ( NH   2 ) 2   , wherein R is a C   2 -C 6    straight - chained or branched, substituted or unsubstituted, saturated or unsaturated, aliphatic hydrocarbon; and        maintaining the mixture at the temperature until the hybrid structure is formed.     
     
     
       32. A method comprising:
   heating a mixture to a temperature effective to form a crystalline organic - inorganic hybrid structure comprising three or more alternating layers, wherein the layers alternate between a bifunctional organic ligand layer and a II - VI semiconductor layer, wherein the II - VI semiconductor layer includes II - VI compounds having the formula MQ, in which each M is independently selected from the group consisting of the II - VI semiconductor cationic species, and each Q is independently selected from the group consisting of S, Se and Te; and        maintaining the mixture at the temperature until the hybrid structure is formed.     
     
     
       33. The method of  claim 32 , wherein each M is independently selected from a group consisting of Zn, Cd, Hg, and Mn. 
     
     
       34. A method comprising:
   heating a mixture to a temperature effective to form a crystalline organic - inorganic hybrid structure comprising three or more layers, wherein the three or more layers alternate between a bifunctional organic ligand layer and a semiconductor layer, and wherein the semiconductor layer includes compounds having the formula MQ, in which each M is independently selected from the group comprising Zn, Cd, Hg, and Mn, and each Q is independently selected from the group consisting of S, Se and Te; and        maintaining the mixture at the temperature until the hybrid structure is formed.