Nanocrystal preparation method, nanocrystals, and apparatus for preparing and storing dissolved gas

A method for preparing nanocrystals, comprising the following steps:

• dissolving, in a first selected solvent, a first precursor which is in a gaseous state under normal temperature and normal pressure, to form a first precursor solution, wherein the first selected solvent has a melting point of lower than 25° C., and a boiling point of higher than 150° C. and when the first precursor is dissolved in the first selected solvent, a temperature of the first selected solvent is set to a value in a range of from 0 to 5° C. from a melting point of the first selected solvent;
• dissolving a second precursor in a second selected solvent to form a second precursor solution, wherein the second precursor is a precursor of a metal element of Group I, Group II, Group III, or Group IV;
• and
• adding, in an inert gas atmosphere, the first precursor solution into a reaction vessel which contains the second precursor solution, wherein the first precursor chemically reacts with the second precursor to generate a nanocrystal;
• wherein when the first precursor solution is added into the second precursor solution, the second precursor solution is in a temperature range of 50-300° C., and after the first precursor solution is added into the second precursor solution, the mixture solution of the first precursor solution and the second precursor solution is maintained at a temperature range of 150-350° C. for a time range of 1 minute to 1 week.