Related Experiment Video
Updated: Nov 18, 2025
04:14
Facile Synthesis of Colloidal Lead Halide Perovskite Nanoplatelets via Ligand-Assisted Reprecipitation
Published on: October 1, 2019
13.3K
Upconversion properties in lanthanide doped layered-perovskite, CsBiNb2O7
Hyeongyu Bae1, Dongcheol Park1, Kyujin Shin1
1Department of Chemistry, Gwangju Institute of Science and Technology, Cheomdangwagi-ro 123, Buk-gu, Gwangju, Republic of Korea.
The Journal of Chemical Physics
|February 9, 2021
Summary
Lanthanide-doped upconversion (UC) materials show promise, but low quantum efficiency limits applications. This study highlights CsBiNb2O7 as a superior host for Yb3+-Er3+ upconversion, outperforming NaYF4 and SrTiO3.
Area of Science:
- Materials Science
- Solid State Chemistry
- Photonics
Background:
- Lanthanide-doped upconversion (UC) materials are crucial for applications like LEDs and bioimaging.
- Low quantum efficiency remains a significant limitation for UC materials.
- Non-centrosymmetric host lattices enhance UC emission by relaxing selection rules for 4f-4f transitions.
Purpose of the Study:
- To compare the upconversion (UC) intensity of Yb3+-Er3+ doped CsBiNb2O7 with other host materials.
- To investigate the UC, downshifting, and double beam system UC properties of CsBiNb2O7.
- To understand the factors limiting UC efficiency, including activator concentration and host-lattice interactions.
Main Methods:
- Synthesized and characterized Yb3+-Er3+ doped CsBiNb2O7, NaYF4, BaTiO3, and SrTiO3.
- Performed comparative upconversion luminescence measurements under NIR excitation.
- Analyzed activator concentration effects and identified quenching mechanisms.
- Investigated double excitation dynamics to understand energy transfer processes.
Main Results:
- CsBiNb2O7 doped with Yb3+-Er3+ exhibited significantly higher UC intensity (2.4x NaYF4, ~70x SrTiO3).
- Optimized Yb3+-Er3+ doping ratios in CsBiNb2O7 revealed dipole-dipole interaction as the primary cause of concentration quenching.
- Downshifting and double beam system UC properties were explored in CsBiNb2O7.
- Double excitation experiments showed a stronger absorption factor than stimulated emission factor in CsBiNb2O7 under 1540 nm irradiation.
Conclusions:
- CsBiNb2O7 is a highly efficient host material for Yb3+-Er3+ co-doped upconversion luminescence.
- Understanding host-dopant interactions, particularly dipole-dipole quenching, is crucial for optimizing UC efficiency.
- Further research into CsBiNb2O7 could lead to improved UC materials for various photonic applications.
Related Concept Videos
03:02Colors and Magnetism
12.9K
Color in Coordination Complexes
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...
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...
12.9K
02:42Valence Bond Theory
10.1K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
10.1K
02:58Crystal Field Theory - Octahedral Complexes
29.0K
Crystal Field Theory
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...
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...
29.0K
02:42Ionic Crystal Structures
16.2K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
16.2K
02:52Stereoisomerism
13.1K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
13.1K
02:58Properties of Transition Metals
28.4K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
28.4K