Active-driven LED is a significant component of modern display technology. It is extensively used in fields such as commercial electronics, medical imaging, education, and scientific research, and has a market worth of 100 billion. Nonetheless, the color purity of existing commercial OLED display technology is low, and traditional III-V group semiconductors-based Micro-LED display technology relies on a high-temperature process and epitaxial substrate. It cannot be integrated with silicon-based circuits, and its technical challenges, such as large-scale transfer, have not been resolved yet.

The team led by Professor Tang Jiang from the School of Optical and Electronic Information and supervisor of ICARE, used thermal evaporation technology in the OLED display industry to prepare PeLEDs devices for industrial applications. However, the long-term low luminous efficiency of thermal evaporation PeLEDs posed a challenge. To address this, the team introduced the TPPO ligand material into the in-situ crystallization process of CsPbBr3 using innovative three-source thermal evaporation technology. The TPPO ligand slowed down the crystal growth kinetic process, resulting in CsPbBr3 nanocrystals with an increased radiation recombination rate. Additionally, TPPO helped passivate the non-radiative resynthesis rate of the crystal surface defects, leading to the generation of high-quality CsPbBr3-TPPO nanocrystalline films in situ, with a fluorescence quantum yield of close to 80%.

The team has successfully integrated PeLEDs and TFT drive backplanes by developing a semi-transparent Mg:Ag top electrode and a corresponding device preparation process. With the integration of top-emitting PeLEDs into the 6.67-inch TFT backplane, the team has achieved an internationally first active driven cesium lead bromide monochrome display panel. These results prove that thermal evaporation PeLED technology is a feasible path to meet the large-scale and pixelated production of cesium lead bromine display panels. It is compatible with existing OLED production lines and equipment and is expected to significantly promote the industrialization process of cesium lead bromine in the display field. Ultimately, this will provide consumers with high-quality display images.