The high-quality single photon source is the basis for realizing light quantum information technology. On the 20th, the reporter learned from Zhejiang University that Fang Wei of the Institute of Optoelectronics of the university cooperated with Jin Yizheng and Peng Xiaogang of the Department of Chemistry for the first time to realize high-purity single photon sources based on colloidal quantum dots at room temperature for practical research and integration. The single photon source opens up a new path. This research paper was published in the journal Nature Communications.
Sunlight, electric light, etc. all emit "photovoltaic" photons, and a single photon source emits at most one photon in a definite period of time. Fang Wei introduced that photon “single line†can realize the quantum effect that quantum communication and light quantum computer must rely on to implement a new generation of technology. Designing and manufacturing an ideal single-photon source that can be integrated and used is always a goal pursued by scientists. Since 2014, Fang Wei and other scholars have tried to use colloidal quantum dots to create new types of single photon sources.
Colloidal quantum dots are a known nanocrystalline material with excellent luminescent properties. The goal that the scientist wants to achieve is: How to make a single quantum dot electrically stimulate at room temperature and emit a photon efficiently. In quantum dots, photons are emitted if electrons recombine with holes. Since electrons in semiconducting materials “run†much faster than holes in the normal state, in order to create a harmonious “composite†in a single quantum dot, it is necessary to balance the rates.
In the state key laboratory of modern optical instruments of Zhejiang University, the reporter saw a piece of transparent fingernail-sized devices. In a structure less than one millimeter thick, they contained clever designs: they wrapped a single colloidal quantum dot with an insulating layer. stand up. This insulating layer slows down the "step" of electrons and also prevents the direct recombination of electrons and holes to produce "stray light." Driven by a voltage of 2.6V, a single colloidal quantum dot was successfully excited. The bright spot of the tip size seen on the screen is exactly the "single line" photons emitted by the colloidal quantum dots. (Reporter Jiang Wei correspondent Zhou Wei)