Alloyed Rod Structure in a Nanocrystalline Quantum Dot

Abstract

A quantum dot includes a nanocrystalline core and an alloyed nanocrystalline shell made of a semiconductor material composition different from the nanocrystalline core. The alloyed nanocrystalline shell is bonded to and completely surrounds the nanocrystalline core.

What is claimed is: 
     
         1 . A quantum dot, comprising:
 an alloyed nanocrystalline core comprising a semiconductor material composition; and   an alloyed nanocrystalline shell comprising a semiconductor material composition different from the nanocrystalline core's semiconductor material composition, the alloyed nanocrystalline shell bonded to and completely surrounding the nanocrystalline core.   
     
     
         2 . The quantum dot of  claim 1 , wherein the alloyed nanocrystalline core's semiconductor material composition comprises two of three chemical elements of the alloyed nanocrystalline shell's semiconductor material composition. 
     
     
         3 . The quantum dot of  claim 1 , wherein the alloyed nanocrystalline core's semiconductor material composition comprises a Group II-VI semiconductor material composition. 
     
     
         4 . The quantum dot of  claim 3 , wherein the Group II-VI semiconductor material composition consists of CdSeS, 
     
     
         5 . The quantum dot of  claim 3 , wherein the alloyed nanocrystalline shell's semiconductor material composition comprises a Group II-VI semiconductor material composition different than the alloyed nanocrystalline core's Group II-VI semiconductor material composition. 
     
     
         6 . The quantum dot of  claim 5 , wherein the alloyed nanocrystalline shell's Group II-VI semiconductor material composition different than the alloyed nanocrystalline core's Group II-VI semiconductor material composition consists of CdZnS. 
     
     
         7 . The quantum dot of  claim 1 , wherein the alloyed nanocrystalline core is an anisotropic alloyed nanocrystalline core. 
     
     
         8 . The quantum dot of  claim 7 , wherein the anisotropic alloyed nanocrystalline core has an aspect ratio between, but not including, 1.0 and 2.0. 
     
     
         9 . The quantum dot of  claim 1 , further comprising an outer nanocrystalline shell bonded to and surrounding the alloyed nanocrystalline shell, the outer nanocrystalline shell comprising a semiconductor material composition different from the alloyed nanocrystalline core's semiconductor material composition and the alloyed nanocrystalline shell's semiconductor material composition. 
     
     
         10 . The quantum dot of  claim 1 , further comprising an insulator layer encapsulating the alloyed nanocrystalline shell. 
     
     
         11 . A quantum dot, comprising:
 a ternary semiconductor nanocrystalline shell; and   a ternary semiconductor nanocrystalline core comprising two of three elements of the ternary semiconductor nanocrystalline shell, the ternary semiconductor nanocrystalline shell bonded to and completely surrounding the semiconductor nanocrystalline core.   
     
     
         12 . The quantum dot of  claim 11 , wherein the ternary semiconductor nanocrystalline shell comprises a first semiconductor material composition, and wherein the ternary semiconductor nanocrystalline core comprises a second semiconductor material composition different than the first semiconductor material composition. 
     
     
         13 . The quantum dot of  claim 12 , wherein the first semiconductor material composition comprises a first Group II-VI semiconductor material composition. 
     
     
         14 . The quantum dot of  claim 13 , wherein the first Group II-VI semiconductor composition consists of CdSeS. 
     
     
         15 . The quantum dot of  claim 12 , wherein the ternary semiconductor nanocrystalline shell consists of a second Group II-VI semiconductor material different than the first Group II-VI semiconductor material. 
     
     
         16 . The quantum dot of  claim 15 , wherein the second Group II-VI semiconductor material is CdZnS. 
     
     
         17 . The quantum dot of  claim 11 , further comprising an outer nanocrystalline shell encapsulating the ternary semiconductor nanocrystalline shell. 
     
     
         18 . The quantum dot of  claim 17 , wherein the outer nanocrystalline shell comprises ZnS. 
     
     
         19 . The quantum dot of  claim 11 , wherein the ternary semiconductor nanocrystalline core is an anisotropic ternary semiconductor nanocrystalline core. 
     
     
         20 . The quantum dot of  claim 19 , wherein the anisotropic ternary semiconductor nanocrystalline core has an aspect ratio between, but not including, 1.0 and 2.0. 
     
     
         21 . The quantum dot of  claim 11 , further comprising a binary outer nanocrystalline shell bonded to and surrounding the ternary semiconductor nanocrystalline shell, the binary outer nanocrystalline shell comprising a semiconductor material composition different from the ternary semiconductor nanocrystalline core and the ternary semiconductor nanocrystalline shell. 
     
     
         22 . The quantum dot of  claim 11 , further comprising an insulator layer encapsulating the ternary semiconductor nanocrystalline shell. 
     
     
         23 . A method of tuning an exciton peak for a quantum dot, the comprising:
 selecting an alloyed nanocrystalline core corresponding to a targeted exciton peak for the quantum dot;   forming the alloyed nanocrystalline core;   forming an alloyed nanocrystalline shell comprising a semiconductor material composition different from the alloyed nanocrystalline core, the alloyed nanocrystalline shell bonded to and completely surrounding the alloyed nanocrystalline core.   
     
     
         24 . The method of  claim 23 , wherein forming the alloyed nanocrystalline core comprises forming a first semiconductor material composition, and wherein forming the alloyed nanocrystalline shell comprises forming a second semiconductor material composition different than the first semiconductor material composition. 
     
     
         25 . The method of  claim 24 , wherein the first semiconductor material composition comprises two of three chemical elements of the second semiconductor material composition. 
     
     
         26 . The method of  claim 23 , wherein forming the alloyed nanocrystalline core comprises forming a Group II-VI semiconductor material composition. 
     
     
         27 . The method of  claim 26 , wherein forming the Group II-VI semiconductor material composition comprises forming a semiconductor material composition consisting of CdSeS. 
     
     
         28 . The method of  claim 26 , wherein forming the alloyed nanocrystalline shell comprises forming a Group II-VI semiconductor material composition different than the alloyed nanocrystalline core's Group II-VI semiconductor material composition. 
     
     
         29 . The method of  claim 28 , wherein forming forming the alloyed nanocrystalline shell's Group II-VI semiconductor material composition comprises forming a semiconductor material composition consisting of CdZnS. 
     
     
         30 . The method of  claim 23 , wherein the exciton peak is approximately 550 nanometers or less.