Two-phase thermal method for preparation of cadmium sulfide quantum dots

US7476599B2 · kind B2 · utility

Assignees

• Changchun Institute of Applied Chemistry · CN
• Chinese Academy of Sciences (CAS) · CN

Inventors

• Qiang Wang · Karlsruhe, DE
• Daocheng Pan · Changchun, CN
• Xiangling Ji · Changchun, CN
• Shichun Jiang · Changchun, CN
• Lijia An · Changchun, CN

Key dates

• Filing date: Jun 21, 2005
• Grant date: Jan 13, 2009
• Expiry date: Aug 2, 2026

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/0259
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A two-phase thermal method for the preparation of cadmium sulfide quantum dots where a cadmium source, a sulfur source and a capping agent are heated in water and water-insoluble organic solvents forming a two-phase system. By means of varying reaction time, cadmium sulfide quantum dots of different sizes can be prepared. Quantum dots already obtained can be used as crystal seeds in the reaction of newly added reaction precursor to give larger sized quantum dots with a size distribution similar to that of the initial crystal seeds so as to realize the control of quantum dot size. The quantum dots obtained in the present invention have relatively narrow size distribution, and emit royal purple or blue light under ultraviolet lamp, with a photoluminescence quantum efficiency of from 3 to 60%.