Changchun Yinghua Institute of Chinese Academy of Sciences has developed high-efficiency green light-emitting diodes

The special structure of quasi-two-dimensional perovskite gives it superior luminescence potential. Although some quasi-two-dimensional perovskite light-emitting diodes have achieved high electro-optical conversion efficiency, when using different organic components, the reason for the low efficiency of some green light devices is still unknown. Recently, Qin Chuanjiang's research group at the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, and Professor Anda Chiba Vector's research group at Kyushu University in Japan have made new progress. Researchers have analyzed a large number of experimental data and found that certain types of organic components are causing device performance The reason for the low, and then developed a high-efficiency green light-emitting diode. Related results were published online in "Nature-Photonics".

At present, most light-emitting diodes are based on inorganic materials, and organic-inorganic hybrid perovskites have received extensive attention in the field of optoelectronic research due to their low cost, ease of processing, and excellent optoelectronic properties. Light-emitting diodes based on such materials also have the potential to become A generation of lighting and display technology.

Qin Chuanjiang, the first author of the paper, said that the organic-inorganic hybrid perovskite used in the study had a crystal structure similar to that of inorganic calcium titanate, while introducing organic components and other inorganic elements. Among them, the three-dimensional perovskite is composed of organic and inorganic components alternately combined in three-dimensional space, the two-dimensional perovskite is a lamellar structure formed by the two components alternately, and the quasi-two-dimensional perovskite is two types of calcium The mixed structure of titanium ore, that is, the three-dimensional perovskite of different sizes is surrounded by a large-sized organic shell layer.

The study found that if organic components with opposite properties are used, the probability of low device performance can be greatly reduced. Based on this, the researchers selected a suitable quasi-two-dimensional perovskite organic component, prepared a green light-emitting diode that can efficiently capture triplet excitons, and achieved an electro-optic conversion efficiency of 12.4%. "The research is expected to be applied in the fields of solar cells, lasers and field effect transistors," Qin Chuanjiang said. (Professor reporter Bu Ye)