KAIST research team develops all-in-one process…”Applicable to next-generation display, solar cell, and optical computing” A process technology that can make high-efficiency light-emitting diodes with perovskite quantum dots, which is attracting attention as a next-generation display light-emitting material, has been developed. KAIST (President Lee Kwang-hyung) announced on the 16th that a research team led by Professor Jeong-yong Lee of the School of Electrical and Electronic Engineering has developed a technology to fabricate high-efficiency RGB pattern light emitting diodes without direct UV or electron beam treatment or solution confinement film on the perovskite quantum dot layer. Perovskite quantum dots are attracting attention as a next-generation display light-emitting material because they have high external quantum efficiency and color purity, and the band gap can be adjusted according to the type and ratio of halide anions inside the quantum dot. However, since insulating organic molecules with long carbon chains surround quantum dots for solvent dispersion, performance is lowered when applied as electronic devices, and the pixel patterning process for making displays is vulnerable to UV and electron beam processing used in the patterning process. There is a difficult problem. The research team improved the performance of the light emitting diode by exchanging the insulating organic ligand (binding molecule) around the perovskite quantum dot with an organic ligand with favorable charge transport. In addition, it was possible to freely change the emission color of the quantum dot thin film through halide anion exchange, which controls the ratio of the halide composition inside the quantum dot. It has developed an all-in-one process that simultaneously performs ligand exchange and halide anion exchange. Furthermore, we proposed a patterning process that converts the color of only a local part of the perovskite quantum dot thin film, and succeeded in producing a light emitting diode patterned with RGB colors at high speed without direct UV and electron beam treatment on the perovskite quantum dot thin film. did. A process schematic diagram of the all-in-one process that simultaneously performs ligand exchange and halide anion exchange of perovskite quantum dots, and a schematic diagram depicting the configuration of perovskite quantum dots corresponding to each step (Source = KAIST) Professor Lee Jung-yong said, “The perovskite quantum dot thin film patterning process developed this time has solved many of the problems faced by the solution process-based perovskite quantum dot patterning process, and will be applicable to the realization of next-generation perovskite quantum dot displays. ” he said. In addition, since color conversion and patterning are free, it is expected to be used in various photoelectric devices such as photodetectors, solar cells, and optical computing devices in the future. This research was carried out with support from the National Research Foundations mid-level research project and nano and material technology development project. The research results were published in the journal ‘Advanced Science’ It was recently published online.
