Promoting Energy Transfer via Manipulation of Crystallization Kinetics of Quasi-2D Perovskites for Efficient Green Light-Emitting Diodes.
Adv Mater
; 33(40): e2102246, 2021 Oct.
Article
em En
| MEDLINE
| ID: mdl-34396606
ABSTRACT
Quasi-2D (Q-2D) perovskites are promising materials applied in light-emitting diodes (LEDs) due to their high exciton binding energy and quantum confinement effects. However, Q-2D perovskites feature a multiphase structure with abundant grain boundaries and interfaces, leading to nonradiative loss during the energy-transfer process. Here, a more efficient energy transfer in Q-2D perovskites is achieved by manipulating the crystallization kinetics of different-n phases. A series of alkali-metal bromides is utilized to manipulate the nucleation and growth of Q-2D perovskites, which is likely associated with the Coulomb interaction between alkali-metal ions and the negatively charged PbBr6 4- frames. The incorporation of K+ is found to restrict the nucleation of high-n phases and allows the subsequent growth of low-n phases, contributing to a spatially more homogeneous distribution of different-n phases and promoted energy transfer. As a result, highly efficient green Q-2D perovskites LEDs with a champion EQE of 18.15% and a maximum brightness of 25 800 cd m-2 are achieved. The findings affirm a novel method to optimize the performance of Q-2D perovskite LEDs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Adv Mater
Assunto da revista:
BIOFISICA
/
QUIMICA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
China