Quantum dot light emitting device comprising three sub-function layers with different surface energy of ligands, preparation method thereof and display apparatus

A quantum dot light emitting device, comprising an anode, one or more light emitting function layers and a cathode which are disposed in a stacked mode, wherein at least one of the one or more light emitting function layers comprises at least two sub-function layers, each of the sub-function layers comprises ligands, and surface energy of the ligands corresponding to the each of the sub-function layers gradiently changes in a transmission direction of carriers in the each of the sub-function layers, so that energy levels of the sub-function layers gradiently change;

• wherein the at least one of the one or more light emitting function layers comprises three sub-function layers;
• wherein the ligands comprise:
• fluorine-containing group ligands with low surface energy as well as hydrophobic amine ligands and hydrophilic amine ligands with high surface energy;
• wherein in response to the light emitting function layers being manufactured on a hydrophilic film layer, the surface energy of the hydrophilic amine ligands is greater than that of the hydrophobic amine ligands;
• and
• in response to the light emitting function layers being manufactured on a hydrophobic film layer, the surface energy of the hydrophobic amine ligands is greater than that of the hydrophilic amine ligands.