{"title":"Enhancement of luminescence and stability of CsPbBr3 quantum dots and their related light-emitting diodes through passivation by guanidine bromide","authors":"Jianping Huang, Fangfang You, Qing Zhang, Yi Yao, Wenhua Zhang, Faqiang Xu","doi":"10.1016/j.jlumin.2025.121196","DOIUrl":null,"url":null,"abstract":"<div><div>All-inorganic perovskite CsPbX<sub>3</sub> (X = Cl, Br, I) quantum dots (QDs) have attracted considerable attention in the fields of light-emitting diodes (LEDs) and displays owing to their excellent photoelectric properties. However, the intrinsic defects and poor stability in QDs limit their practical application. In order to address these problems, this study introduced guanidine bromide (GABr) as modifying agent during the synthesis of CsPbBr<sub>3</sub> QDs using the ligand-assisted reprecipitation method. From XRD and TEM studies, the introduction of GABr effectively enhances the crystallinity and adjusts the morphology of QDs without altering the crystal structure. The XPS and FTIR results revealed that the GA group not only fills the halogen vacancy defects by replacing part of the long-chain organic ligand Octanoic acid (OTAc), but also effectively passivate the unsaturated Pb forming a stable CsPbBr<sub>3</sub> QD with tri-ligand and optimized optical property and stability. As the confirmation of the passivation effects, the perovskite LEDs (PeLEDs) devices with CsPbBr<sub>3</sub> QDs as emission layers (EMLs) were fabricated and the maximum EQE and luminance for the passivated EML are nearly two times higher than that of primeval CsPbBr<sub>3</sub> QDs devices, and the spectral stability of electroluminescence is obviously enhanced. This work provides a straightforward passivation strategy for preparing efficient and stable CsPbBr<sub>3</sub> QDs and related optoelectronic devices.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"281 ","pages":"Article 121196"},"PeriodicalIF":3.3000,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Luminescence","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S002223132500136X","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 0
Abstract
All-inorganic perovskite CsPbX3 (X = Cl, Br, I) quantum dots (QDs) have attracted considerable attention in the fields of light-emitting diodes (LEDs) and displays owing to their excellent photoelectric properties. However, the intrinsic defects and poor stability in QDs limit their practical application. In order to address these problems, this study introduced guanidine bromide (GABr) as modifying agent during the synthesis of CsPbBr3 QDs using the ligand-assisted reprecipitation method. From XRD and TEM studies, the introduction of GABr effectively enhances the crystallinity and adjusts the morphology of QDs without altering the crystal structure. The XPS and FTIR results revealed that the GA group not only fills the halogen vacancy defects by replacing part of the long-chain organic ligand Octanoic acid (OTAc), but also effectively passivate the unsaturated Pb forming a stable CsPbBr3 QD with tri-ligand and optimized optical property and stability. As the confirmation of the passivation effects, the perovskite LEDs (PeLEDs) devices with CsPbBr3 QDs as emission layers (EMLs) were fabricated and the maximum EQE and luminance for the passivated EML are nearly two times higher than that of primeval CsPbBr3 QDs devices, and the spectral stability of electroluminescence is obviously enhanced. This work provides a straightforward passivation strategy for preparing efficient and stable CsPbBr3 QDs and related optoelectronic devices.
期刊介绍:
The purpose of the Journal of Luminescence is to provide a means of communication between scientists in different disciplines who share a common interest in the electronic excited states of molecular, ionic and covalent systems, whether crystalline, amorphous, or liquid.
We invite original papers and reviews on such subjects as: exciton and polariton dynamics, dynamics of localized excited states, energy and charge transport in ordered and disordered systems, radiative and non-radiative recombination, relaxation processes, vibronic interactions in electronic excited states, photochemistry in condensed systems, excited state resonance, double resonance, spin dynamics, selective excitation spectroscopy, hole burning, coherent processes in excited states, (e.g. coherent optical transients, photon echoes, transient gratings), multiphoton processes, optical bistability, photochromism, and new techniques for the study of excited states. This list is not intended to be exhaustive. Papers in the traditional areas of optical spectroscopy (absorption, MCD, luminescence, Raman scattering) are welcome. Papers on applications (phosphors, scintillators, electro- and cathodo-luminescence, radiography, bioimaging, solar energy, energy conversion, etc.) are also welcome if they present results of scientific, rather than only technological interest. However, papers containing purely theoretical results, not related to phenomena in the excited states, as well as papers using luminescence spectroscopy to perform routine analytical chemistry or biochemistry procedures, are outside the scope of the journal. Some exceptions will be possible at the discretion of the editors.