Quantum dot light enhancement substrate and lighting device including same
摘要
說明書
The ability to control and separate the nucleation and growth environments is in large part provided by selecting the appropriate high-boiling organic molecules used in the reaction mixture during the QD synthesis. Example of high-boiling solvents typically include organic molecules made up of a functional head including, for example, a nitrogen, phosphorous, or oxygen atom, and a long hydrocarbon chain. The functional head of the molecules attach to the QD surface as a monolayer or multilayer through covalent, dative, or ionic bonds and are referred to as capping groups. The capping molecules present a steric barrier to the addition of material to the surface of a growing crystallite, significantly slowing the growth kinetics. It is desirable to have enough capping molecules present to prevent uncontrolled nucleation and growth, but not so much that growth is completely suppressed.
This colloidal synthetic procedure for the preparation of semiconductor QDs provides a great deal of control and as a result the synthesis can be optimized to give the desired peak wavelength of emission as well as a narrow size distribution. This degree of control is based on the ability to change the temperature of injection, the growth time, as well as the composition of the growth solution. By changing one or more of these parameters the size of the QDs can be engineered across a large spectral range while maintaining good size distributions.
