Related Experiment Video
Updated: Mar 25, 2026
Low-energy Cathodoluminescence for OxyNitride Phosphors
Published on: November 15, 2016
Localized Excitonic Magnetic Polarons and Their Role in the Luminescence of Rare-Earth-Sulfur Codoped Divalent Metal
Jiaren Huang1, Xiaodong Shen1, Yongqiang Zhao1
1State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures; Guangxi Key Laboratory of Nonferrous Metals and Specialty Materials Processing, Guangxi University, Nanning 530004, China.
Abstract:
In this work, BaCl2:Eu2+,S2- is employed as model system to investigate the formation and tunable evolution of localized excitonic magnetic polarons (LEMPs) in Eu-S codoped divalent metal halides, in which Eu-S bonding in BaCl2 with Eu2+ 5d-f hybridization markedly enhances the band edge emission, shifting from 401 to 412 nm with rising EuS content, and the absorption band edge shifts from 3.02 to 2.85 eV, with EMP character. Moreover, EuS doped in different hosts (Ba < Sr < Ca) leads to a progressive red shift of EMP emission from 406 nm to the near-infrared region. Under high-energy laser excitation, these compounds can exhibit pronounced nonlinear emission with ASE-like behavior (n > 1), demonstrating the LEMP-cooperative radiative processes. This study establishes rare-earth-sulfur codoped halides as a promising materials platform for tuning luminescence through coupled spin-lattice-exciton interactions.
Related Concept Videos
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
01:23Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...
02:42Valence Bond Theory
01:26Variables Affecting Phosphorescence and Fluorescence
01:14Photoluminescence: Applications
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...