Ultra-Stable and Highly Efficient White Light Emitting Diodes through CsPbBr3 Perovskite Nanocrystals−Silica Composite Phosphor Functionalized with Surface Phenyl Molecules

Soyeon Yoon, Minjun Seo, In Soo Kim, Kwangyeol Lee, Kyoungja Woo

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

Poor stability of CsPbBr3 perovskite nanocrystals (NCs) to moisture/heat/light has significantly limited their application as a green phosphor, despite their outstanding luminescent properties. Here, a remarkably stable CsPbBr3 NCs−silica composite phosphor functionalized with surface phenyl molecules (CsPbBr3−SiO2Ph) is synthesized by controlling low-temperature hydrolysis and condensation reaction of perhydropolysilazane in the presence of CsPbBr3 NCs followed by phenyl-functionalization. Through the process, CsPbBr3 NCs are confined in a compact silica matrix, which is impermeable to H2O. The synthesis strategy is extended to a classical red quantum dot, CdZnSeS@ZnS NCs, to fabricate a white light emitting diode (WLED) consisting of CsPbBr3−SiO2Ph and CdZnSeS@ZnS−SiO2Ph phosphor and silicone resin packaged on a commercial blue InGaN chip with luminous efficacy (LE) of 9.36 lm W−1. The WLED undergoes enhancements in both green and red photoluminescence over time to achieve a highly efficient performance of 38.80 lm W−1. More importantly, the WLED exhibits unprecedented operational stability of LE/LE0 = 94% after 101 h-operation at 20 mA (2.56 V). The ultra-high operational stability and efficient performance are mainly attributed to thermal curing and aging through which grain growth occurs as well as deactivation of defect states by permeated atmospheric O2.

Original languageEnglish
Article number2206311
JournalSmall
Volume19
Issue number7
DOIs
Publication statusPublished - 2023 Feb 15

Bibliographical note

Publisher Copyright:
© 2022 The Authors. Small published by Wiley-VCH GmbH.

Keywords

  • aging
  • compact silica
  • enhanced photoluminescence
  • operational stability
  • thermal curing

ASJC Scopus subject areas

  • General Chemistry
  • Engineering (miscellaneous)
  • Biotechnology
  • General Materials Science
  • Biomaterials

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