Surface Halogen Compensation for Robust Performance Enhancements of CsPbX3 Perovskite Quantum Dots

Understanding the subtle structure–property relationships of quantum dots (QDs) is essential for targeted modulation of optoelectronic properties, and the influences of surface defects of inorganic halide perovskite (HP) QDs are still not very clear. Here, the negative exciton trapping effects of su...

Full description

Saved in:
Bibliographic Details
Published in:Advanced optical materials 2019-06, Vol.7 (11), p.n/a
Main Authors: Yang, Dandan, Li, Xiaoming, Wu, Ye, Wei, Changting, Qin, Zhengyuan, Zhang, Chunfeng, Sun, Zhiguo, Li, Yuelei, Wang, Yue, Zeng, Haibo
Format: Article
Language:English
Subjects:
defect passivation
Emission analysis
exciton dynamics
Excitons
inorganic halide perovskites
Materials science
Octahedrons
Optical properties
Optics
Optoelectronics
Organic chemistry
Organic light emitting diodes
Perovskites
Photoluminescence
Quantum dots
Quantum efficiency
Surface defects
surface halide vacancies
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Understanding the subtle structure–property relationships of quantum dots (QDs) is essential for targeted modulation of optoelectronic properties, and the influences of surface defects of inorganic halide perovskite (HP) QDs are still not very clear. Here, the negative exciton trapping effects of surface halide vacancies (VX) on the photoluminescence quantum yield QY (PLQY) of HPQDs are determined by a detailed analysis of the optical parameters, exciton dynamics, and surface chemical states. Based on the fact that VX contribute greatly to nonradiative recombination processes, versatile in situ and postpassivation strategies are developed by constructing intact Pb–X octahedrons. High QYs for standard red CsPbBr1I2 (85%), green CsPbBr3 (96%), and blue CsPbBr1.3Cl1.7 (92%) emissions are achieved. The superiorities of the reduced VX are further demonstrated by high external quantum efficiency of 0.8% and a stable emission wavelength of the blue light‐emitting diodes. This study deepens the understanding of HPQDs and demonstrates the potential for the artificial control of the optical properties of HPQDs. Surface halide vacancy (VX) defects in halide perovskite quantum dots are found to make great contributions to the nonradiative recombination processes, so that reducing the surface VX density is favorable for improving optical properties. Therefore, specific in situ and postpassivation strategies by constructing intact Pb–X octahedrons are developed to reduce the surface VX and enhance the quantum yield.
ISSN:2195-1071
2195-1071
DOI:10.1002/adom.201900276