Blue light cadmium-free quantum dot, preparation method thereof and quantum dot photoelectric device

Abstract

The invention discloses a blue light cadmium-free quantum dot, a preparation method thereof and a quantum dot light-emitting device. The preparation method of the cadmium-free quantum dot comprises the following steps that S1, an indium precursor, a first ligand and a solvent are mixed to prepare an indium-first ligand solution, the first ligand is a long-chain carboxylic acid ligand with the carbon number being 10-18, and the ratio of the amount of substance of carboxylate radicals of the first ligand to the amount of substance of indium ions of the indium precursor is (1: 2)-(5: 2); S2, short-chain zinc salt and a second ligand are added into the indium-first ligand solution to form a cation-mixed ligand solution, and at least part of the short-chain zinc salt and the second ligand are bonded through coordination bonds; S3, a phosphorus precursor is added into the cation-mixed ligand solution to react to obtain a solution containing indium zinc phosphide quantum dots. The InZnP quantum dot core with small size and few defects is prepared by introducing the short-chain zinc salt in the nucleation process of the quantum dot, and the introduction of the Zn element also optimizes theenergy band structure of the quantum dot so that the quantum dot with the luminescence range of 470-490nm is obtained.

Description

Technical field [0001] The invention relates to the technical field of quantum dot materials, in particular to a blue cadmium-free quantum dot, a preparation method thereof, and a quantum dot optoelectronic device. Background technique [0002] Quantum dots are semiconductor nanocrystals formed by hundreds or thousands of atoms. Due to their quantum confinement effect, quantum dots have unique optoelectronic properties and have broad application prospects in new displays, biomarkers, lasers and other fields. In particular, the research on quantum dot light-emitting diodes, using blue, green and red quantum dots as light-emitting layers, is expected to become a new technological route in the display industry. In the past thirty years, CdSe quantum dots have been widely studied due to their high fluorescence quantum efficiency and narrow half-width. However, the presence of the toxic heavy metal Cd can cause major environmental problems and is an important obstacle to its large-sc...

AI Technical Summary

Problems solved by technology

[0007] However, due to the fact that the intrinsic InP structure itself is covalently bonded, the nucleation uniformity is poor, resulting in a wide half-width of the blue-emitting InP, generally above 45nm.

The luminescence performance and stability of InP quantum dots obtained by etching are poor, and the preparation process uses strong corrosive chemicals, which is difficult for industrial application

The crystallization of InP quantum dots synthesized at low temperature is not complete, and it is difficult to form a crystal structure with strong stability, resulting in poor stability, and subsequent high-temperature coating cannot be performed, and the luminous efficiency is low.

Images