Perovskite Quantum Dots for High-performance Light-emitting Diodes Were Developed

2022-03-09 L  M  S 】

  Perovskite quantum dots are a new type of optoelectronic materials developed in recent years. With excellent optical and electronic properties such as high photoluminescence quantum yield, high brightness, high defect tolerance, and the color gamut meeting the BT. 2020 standard, Perovskite quantum dots show increasing application prospects in the field of light-emitting diodes (LED) and new displays. However, factors like large specific surface area, surface-related trap states and the surface organic insulating ligands have serious negative effects on their fluorescence quantum yield and device performance.

  To address the above issues, theNew Display Technology Group of the Institute of Semiconductors, Guangdong Academy of Sciences, with their collaborators from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, reported a simple method of preparing high-performance electroluminescent devices with high-valent metal Ga-modified CsPbBr3 QDs. It demonstrated that Ga cations can passivate the surface defects of QDs, giving rise to balanced interfacial electrical properties of QDs by organic ligand and Ga ions. Consequently, a higher PLQY, longer PL lifetime, and better carrier transport performance can be achieved for the Ga-modified CsPbBr3 QDs compared with the pristine ones.

  The Perovskite QDs-based LEDs fabricated with Ga ions modified QDs as emitting layers present a remarkably improved performance compared with the pristine CsPbBr3 based devices. The highest luminance value, maximum CE and operational stability can be respectively increased by 2 times, 9 times and 7 times. This study paves the way towards the preparation of highly efficient all inorganic Perovskite QDs-based LEDs by using the Ga(III) cations passivation strategy.

  This work is published in Journal of Materials Chemistry C. Dr. Jiantai Wang from the Institute of Semiconductors was the first author. The New Display Technology Team leader Dr. Zheng Gong and Professor Zhiyuan Xie from the Changchun Institute of Applied Chemistry were co-corresponding authors.

  The paper information: Wang, J., Xu, Y., Zou, S., Pang, C., Cao, R., Pan, Z., Guo, C., Hu, S., Liu, J., Xie, Z., & Gong, Z. (2021). Effective defect passivation of CsPbBr3 quantum dots using gallium cations toward the fabrication of bright perovskite LEDs. Journal of Materials Chemistry C.