Perovskite CsPbBr1.2I1.8 quantum dot alloying for application in white light-emitting diodes with excellent color rendering index

• Published in: Journal of alloys and compounds Vol. 708; pp. 517 - 523
• Main Authors: Zhou, Jiangcong, Hu, Zhibiao, Zhang, Lizong, Zhu, Yu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.06.2017
• Subjects: Color rendering index; Light-emitting diode; Perovskite; Phosphors; Quantum dot; Stable CsPbBr1.2I1.8 quantum dots; Perovskite; Color rendering index; Quantum dot; Phosphors; Light-emitting diode; Stable CsPbBr1.2I1.8 quantum dots
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.03.043

Halide perovskites as novel optoelectronic materials have been considered to be good candidates as efficient luminescence converters for light-emitting diodes. In this work, the alloying CsPbBr1.2I1.8 quantum dots (QDs) and perovskite CsPbI3 QDs were synthesized, and their phase structure, morphology and luminescence toward humidity were investigated. Compared with CsPbI3 QDs, the alloying CsPbBr1.2I1.8 QDs displayed more stable cubic phase and better resistance to moisture. In addition, the enhanced phase-stability has been explained. Furtherly, the CsPbBr1.2I1.8 QDs were used as red-emitting phosphors to improve the performance of white light-emitting diodes (WLED), and the as-fabricated WLED showed high luminous efficiency and excellent color rendering index (Ra), which indicated that the CsPbBr1.2I1.8 QDs were promising red-emitting materials. Significantly, the values of Ra and correlated color temperature (CCT) were basically stable with the variation of operation current, implying the excellent color stability of CsPbBr1.2I1.8 QDs-modified WLED. Alloying CsPbBr1.2I1.8 QDs exhibit stable cubic perovskite structure and better resistance to moisture for the application in WLED with high luminous efficiency and excellent color rendering index. [Display omitted] •Tuning chemical composition was proposed to stabilize the perovskite structure.•The alloying QDs displayed stable cubic phase and good resistance to moisture.•The WLED showed high luminous efficiency and excellent color rendering index.