Enhancing the light-emitting performance and stability in CsPbBr 3 perovskite quantum dots via simultaneous doping and surface passivation

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2020-10, Vol.8 (41), p.14439-14445
• Main Authors: Yang, Hengxiang, Yin, Wenxu, Dong, Wei, Gao, Long, Tan, Ching-Hong, Li, Wubo, Zhang, Xiaoyu, Zhang, Jiaqi
• Format: Article
• Language: English
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/D0TC03510F

Inorganic perovskite CsPbBr 3 quantum dots (QDs) have emerged as a promising candidate for optoelectronic applications due to their narrow emission and color purity, among other things. However, it remains a challenge to produce QDs with the desired brightness and stability. Here, a one-step synthesis with a doping agent Co(AC) 2 is demonstrated to produce CsPbBr 3 QDs the photoluminescence quantum yield (PLQY) and stability of which improve to almost 90% and by over 65% to 50 days, respectively. It has been elucidated by microscopy and XRD results that the Co 2+ doping optimizes the quantum dot octahedron structure, indicating more passivated QD defects. As a result, LED devices using doped CsPbBr 3 QDs as the luminescent layer show about 47% improvement in luminance. We postulate that, owing to the weaker electronegativity of COO − than that of Br − , the electrovalent bond on Pb is stronger, resulting in the inhibition of defect formation.