Alloyed Quantum Dots with Tuned Exciton Wave Function Delocalization for Enhanced Energy Transfer.
Jia Luo1, Yanhong Fan1, Yanchao Zhao1
1South China Advanced Institute for Soft Matter Science and Technology, Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
The Journal of Physical Chemistry Letters
|February 23, 2026
Summary
Tellurium doping in lead selenide quantum dots (QDs) enhances exciton energy transfer by controlling delocalization. This boosts upconversion efficiency significantly, offering a new route for QD material design.
Area of Science:
- Materials Science
- Nanotechnology
- Photochemistry
Background:
- Efficient exciton energy transfer in quantum dots (QDs) is crucial for advanced applications.
- Controlling exciton wave function delocalization is key to optimizing energy transfer but remains difficult.
- Lead selenide (PbSe) quantum dots are promising but require improved energy transfer mechanisms.
Purpose of the Study:
- To modulate exciton delocalization and enhance energy transfer in quantum dots.
- To investigate the effect of tellurium (Te) doping in PbSe QDs on energy transfer efficiency.
- To utilize a QD-sensitized triplet-triplet annihilation upconversion system to evaluate energy transfer performance.
Main Methods:
- Engineering the exciton Bohr radius in lead selenide telluride (PbSe$_{1-x}$Te$_{x}$) alloy quantum dots via tellurium doping.
- Utilizing a quantum dot-sensitized triplet-triplet annihilation upconversion system.
- Employing femtosecond transient absorption microscopy to study exciton dynamics.
Main Results:
- Tellurium doping in PbSe QDs significantly enhances energy transfer and boosts upconversion efficiency by up to 50-fold.
- Optimized Te doping accelerates early-stage exciton transfer dynamics in QD thin films, indicating increased exciton delocalization.
- Shortening surface ligands further improves energy transfer and upconversion performance in PbSe$_{1-x}$Te$_{x}$ QDs.
Conclusions:
- Tellurium doping is an effective strategy to tune exciton delocalization and enhance energy transfer in quantum dots.
- This approach provides a versatile material-design route for optimizing energy transfer in QD-based systems.
- The findings pave the way for improved performance in various quantum dot applications.
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