Core-Localized Cu Dopants Pin Red Emission in Multinary Ag-Based Quantum Dots
Kaiyue Liu1, Tongzhou Li1, Shikang Zhang1
1School of Materials Science and Engineering, Ocean University of China, No. 1299, Sansha Road, Huangdao District, Qingdao 266404, China.
Nano Letters
|May 7, 2026
Summary
We stabilized red emission from copper-doped quantum dots by confining dopants within a core-shell structure. This approach enhances spectral stability and boosts the efficiency of luminescent solar concentrators by minimizing reabsorption.
Area of Science:
- Materials Science
- Quantum Dot Technology
- Photovoltaics
Background:
- Alloy-disordered quantum dots often sacrifice spectral stability for efficiency.
- Reabsorption in quantum dots limits the performance of photon-transport devices.
Purpose of the Study:
- To develop quantum dots with spectrally stable and efficient red emission.
- To improve the performance of luminescent solar concentrators by mitigating reabsorption.
Main Methods:
- Confining Cu(I) dopants within Ag-In-Ga-S cores during GaSₓ overgrowth.
- Utilizing Cu-valence fingerprints and elemental mapping for structural verification.
- Performing single-dot spectroscopy and first-principles calculations.
Main Results:
- Achieved spectrally pinned red emission with a constant Stokes shift (∼140 meV).
- Resolved symmetric Lorentzian lines down to ∼62 meV via single-dot spectroscopy.
- Identified substitutional CuAg as a low-energy defect responsible for spectral pinning.
- Obtained photoluminescence quantum yields up to 85%.
Conclusions:
- Cu-doped core-shell quantum dots offer enhanced spectral stability and high efficiency.
- The developed quantum dots significantly improve luminescent solar concentrator optical efficiency (7.33%) by reducing reabsorption.
