The new display team of the Institute of Semiconductors of the Guangdong Academy of Sciences cooperated with relevant teams of the Changchun Institute of Applied Chemistry of the Chinese Academy of Sciences to develop high-performance perovskite quantum dots and successfully applied them to light-emitting diodes. Relevant research was recently published in "Journal of Materials Chemistry C". Dr. Wang Jiantai is the first author of the paper, and Dr. Gong Zheng and Researcher Xie Zhiyuan are the joint corresponding authors.
Perovskite quantum dots are a new type of optoelectronic material developed in recent years. Due to their advantages such as high fluorescence quantum efficiency, high brightness, high defect tolerance, and color gamut that meets the BT.2020 standard, they are widely used in Light-emitting diodes (LEDs) and new display fields have broad application prospects. However, surface defects of perovskite quantum dots and the insulating properties of surface organic ligands have a significant impact on their fluorescence quantum efficiency and optoelectronic device performance.
Researchers used high-valent metal gallium ions to passivate the surface of all-inorganic perovskite quantum dots CsPbBr3 to prepare a CsPbBr3 electroluminescent device with high photoelectric efficiency. This work focuses on the surface passivation mechanism and performance effects of metal gallium ion source on CsPbBr3 quantum dots.
The research results show that the modification of metal gallium ions significantly reduces the density of defect states on the surface of CsPbBr3 quantum dots and improves the fluorescence quantum efficiency. At the same time, the partial replacement of organic ligands on the surface of quantum dots by gallium ions improves the loading rate. Current transport capability. Compared with quantum dot devices without gallium ion modification, electroluminescent devices prepared based on this quantum dot material have a maximum brightness that is twice as high, a current efficiency that is more than nine times more efficient, and a device life that is more than seven times longer.
This method solves the problem of the impact of quantum dot surface defects on device performance, and develops a method for passivating quantum dot defects in this system.
Related paper information: https://doi.org/10.1039/D1TC01077H