Nanocrystals including a group IIIA element and a group VA element, method, composition, device and other products

A method for preparing a nanocrystal comprising a semiconductor material including one or more elements of Group IIIA of the Periodic Table of Elements and one or more elements of Group VA of the Periodic Table of Elements, the method comprising:

• dispersing or dissolving one or more Group IIIA precursors in a first solvent to form one or more Group IIIA reactants, wherein the first solvent comprises a coordinating solvent and/or a non-coordinating solvent;
• dispersing or dissolving one or more Group VA precursors in a second solvent to form one or more Group VA reactants;
• simultaneously and separately adding the one or more Group IIIA reactants and one or more Group VA reactants to a reaction medium including a third solvent and a ligand source to form a reaction mixture;
• and
• reacting one or more Group IIIA reactants with one or more Group VA reactants in the presence of a ligand source to form nanocrystals comprising the semiconductor material and having one or more ligands attached to at least a portion of the nanocrystals.

A method for preparing a nanocrystal comprising a semiconductor material including one or more elements of Group IIIA of the Periodic Table of Elements and one or more elements of Group VA of the Periodic Table of Elements, the method comprising:

• dispersing or dissolving one or more Group IIIA precursors in a first solvent to form one or more Group IIIA reactants, wherein the first solvent comprises a coordinating solvent and/or a non-coordinating solvent;
• dispersing or dissolving one or more Group VA precursors in a second solvent to form one or more Group VA reactants;
• separately adding the one or more Group IIIA reactants and the one or more Group VA reactants to a reaction medium including a third solvent and a ligand source to form a reaction mixture, and
• reacting the reaction mixture under conditions sufficient to form nanocrystals comprising the semiconductor material having a predetermined composition, predetermined size, and predetermined emission characteristics, at least a portion of the nanocrystals including one or more ligands attached thereto.

A light emitting device comprising:

• a substrate;
• a first electrode adjacent to the substrate;
• a second electrode opposed to the first electrode;
• and
• a plurality of nanoerystals disposed between the first electrode and the second electrode, wherein the nanocrystals comprise a nanocrystal comprising a core comprising a first semiconductor material comprising one or more elements of Group IIIA of the Periodic Table of Elements and one or more elements of Group VA of the Periodic Table of Elements, and a shell disposed over at least a portion of a surface of the core, the shell comprising one or more additional semiconductor materials, wherein the nanocrystal is capable of emitting visible light having a photoluminescence quantum efficiency of at least about 30% upon excitation and wherein the device further includes less than 1,000 ppm Pb, less than 100 ppm Cd, and less than 1,000 ppm Hg.