Researchers from Northwestern University developed a perovskite quantum-dots based emitter that features high stability, self-healing and very high brightness.
Perovskite QDs can realize single photon emission at room temperature and have excellent optical properties. The research team has developed a unique spray-synthesis method to create these pQDs which greatly increases the contact area of two different solutions, making it possible to grow a uniform protective organic layer on the surface of the quantum dots.
The QDs produced in this method retain their brightness even after 24 hours of intensive continuous excitation, indicating that they could overcome the poor stability of perovskite quantum dots.
The team was surprised to learn that the perovskite quantum dots prepared in this way also have a unique self-healing ability. Although the quantum dots are damaged and decayed by extremely high-intensity excitation, they retrieve their original brightness after "resting" for just a few minutes.
The researchers say that a perovskite quantum emitter prepared by this spray synthesis method requires only about 1% of the excitation intensity needed for other quantum emitters, and its single-photon brightness is as high as 9 million photons per second, which is a new world record. In addition, its single-photon purity is quite high as 98%.