Ligand-modified quantum dot composition, ligand-modified quantum dot layer, preparation methods thereof, quantum dot light emitting diode

A method for preparing a ligand-modified quantum dot composition, comprising:

• synthesizing a first ligand-modified quantum dot in presence of a first ligand modifier in a solvent;
• adding a second ligand modifier to the first ligand-modified quantum dot, wherein the second ligand modifier has a structural formula of segment A-segment B, wherein the segment B is a chain-cleavable long molecular chain, and wherein the second ligand modifier displaces the first ligand such that the segment A of the second ligand modifier is adsorbed on a surface of the quantum dot to obtain a second ligand-modified quantum dot;
• and
• separating the second ligand-modified quantum dot from the first ligand,
• wherein the segment B includes an R1 group, an R2 group and an R3 group which are sequentially linked one by one, and the R1 group is linked to the segment A, and the R2 group is cleavable,
• wherein the R2 group includes a group that is photodegraded or thermally degraded, and a chemical bond between the R2 group and the R1 group is broken under heating or illumination, and
• wherein the R2 group is selected from a group consisting of a peroxy group (—O—O—) and a diacyl peroxide