Related Experiment Video
Updated: Nov 3, 2025
11:26
Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light
Published on: September 12, 2014
12.8K
Intramolecular Triplet-Triplet Annihilation Photon Upconversion in Diffusionally Restricted Anthracene Polymer
Fredrik Edhborg1, Hakan Bildirir1, Pankaj Bharmoria1
1Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden.
The Journal of Physical Chemistry. B
|June 3, 2021
Summary
Developing solid-state photon upconversion systems is crucial for technology. This study demonstrates efficient intramolecular triplet-triplet annihilation photon upconversion (TTA-UC) in polymers, outperforming traditional methods.
Area of Science:
- Materials Science
- Photochemistry
- Polymer Chemistry
Background:
- Triplet-triplet annihilation photon upconversion (TTA-UC) is essential for developing advanced optical materials.
- Current TTA-UC systems often face limitations in solid-state applications due to diffusion-dependent energy transfer.
- Intramolecular energy transfer offers a promising route to overcome these limitations in solid-state TTA-UC.
Purpose of the Study:
- To investigate and demonstrate efficient intramolecular TTA-UC (iTTA) within a polymeric annihilator network.
- To isolate and analyze the iTTA process, distinguishing it from intermolecular TTA (xTTA).
- To explore the kinetics and performance of polymeric iTTA systems for solid-state applications.
Main Methods:
- Design of a specific annihilator polymer to facilitate intramolecular energy transfer.
- Experimental conditions were carefully chosen to isolate iTTA emission.
- Comparison of the polymeric iTTA system with a conventional monomeric xTTA system.
Main Results:
- Successfully demonstrated photon upconversion governed by iTTA within polymer particles.
- Eliminated competing xTTA pathways, providing clear mechanistic insights into iTTA.
- Polymeric iTTA exhibited high efficiency even at very low annihilator concentrations.
- Achieved significantly faster overall kinetics compared to monomeric systems.
Conclusions:
- Intramolecular photon upconversion within polymer networks is a highly effective strategy for solid-state applications.
- Polymeric iTTA offers superior performance, including efficiency and speed, compared to traditional xTTA systems.
- This approach paves the way for developing advanced, efficient solid-state photon upconversion materials.
Related Concept Videos
01:25Deactivation Processes: Jablonski Diagram
1.2K
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
1.2K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.6K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.6K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.0K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
2.0K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.3K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.3K
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
2.1K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
2.1K
01:17Radical Chain-Growth Polymerization: Chain Branching
2.2K
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
2.2K