SEMICONDUCTOR NANOCRYSTALS, METHODS FOR MAKING SAME, COMPOSITIONS, AND PRODUCTS

摘要

A semiconductor nanocrystal characterized by having a solid state photoluminescence external quantum efficiency at a temperature of 90°C or above that is at least 95% of the solid state photoluminescence external quantum efficiency of the semiconductor nanociystal at 25°C is disclosed. A semiconductor nanociystal having a multiple LO phonon assisted charge thermal escape activation energy of at least 0.5eV is also disclosed. A semiconductor nanociystal capable of emitting light with a maximum peak emission at a wavelength in a range from 590 nm to 650 nm characterized by an absorption spectrum, wherein the absorption ratio of OD at 325 nm to OD at 450 nm is greater than 5.5. A semiconductor nanociystal capable of emitting light with a maximum peak emission at a wavelength in a range from 545 nm to 590 nm characterized by an absorption spectrum, wherein the absorption ratio of OD at 325 nm to OD at 450 nm is greater than 7. A semiconductor nanocrystal capable of emitting light with a maximum peak emission at a wavelength in a range from 495 nm to 545 nm characterized by an absorption spectrum, wherein the absorption ratio of OD at 325 nm to OD at 450 nm is greater than 10. A composition comprising a plurality of semiconductor nanocrystals wherein the solid state photoluminescence efficiency of the composition at a temperature of 90°C or above is at least 95% of the solid state photoluminescence efficiency of the composition 25°C is further disclosed. A method for preparing semiconductor nanocrystals comprises introducing one or more first shell chalcogenide precursors and one or more first shell metal precursors to a reaction mixture including semiconductor nanociystal cores, wherein the first shell chalcogenide precursors are added in an amount greater than the first shell metal precursors by a factor of at least about 2 molar equivalents and reacting the first shell precursors at a first reaction temperature of at least 300°C to form a first shell on the semiconductor nanocrystal cores. Populations, compositions, components and other products including semiconductor nanocrystals of the invention are disclosed. Populations, compositions, components and other products including semiconductor nanocrystals made in accordance with any method of the invention is also disclosed.