Quantum dot electroluminescent device and preparation method thereof

The invention discloses a quantum dot electroluminescent device and a preparation method thereof. In order to reduce the hole injection barrier of a quantum dot light emitting diode device, small molecular materials containing polar coordination groups of lone pair electrons, such as materials containing amino groups, mercapto groups or phosphorus groups, are dissolved in a proton solvent throughin-situ ligand replacement and the obtained product is applied to a filmed quantum dot layer after heat treatment during the preparation of the quantum dot light emitting diode device. Because of thepolar coordination groups (amino groups, mercapto groups and phosphorus groups) of lone pair electrons, a larger interface dipole is introduced, the hole injection barrier is reduced, the hole electron flow is balanced, and the device performance is improved. The surface defects of the quantum dot film are passivated, and exciton quenching is reduced. The method has the characteristics of wide applicability, high efficienc