Enhanced Upconversion Performance in Alloyed CdSe(Te)/CdS1–xSex/CdSe Core/Rod/Emitter Nanostructures
| Autor: | Jill M. Cleveland, Christopher C. Milleville, Matthew F. Doty, Eric Y. Chen, Kyle R. Lennon, M O Zide Joshua |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Photoluminescence business.industry Physics::Optics Quantum yield 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Photon upconversion 0104 chemical sciences law.invention law Quantum dot Solar cell Optoelectronics Nanorod Quantum efficiency 0210 nano-technology Absorption (electromagnetic radiation) business |
| Zdroj: | 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC). |
| DOI: | 10.1109/pvsc.2018.8547856 |
| Popis: | Colloidal quantum dot (QD) nanostructures have been shown to convert multiple low-energy photons into a single, high-energy photon through a process called photon upconversion. QD nanostructures could replace conventional upconverter materials in solar cell applications and can be tuned to absorb photons transparent to the host cell and emit usable photons, increasing the short circuit current of the host cell while maintaining open circuit voltage. Double QDs (coupled via a nanorod) have previously demonstrated 0.1% upconversion efficiency and a peak-to-peak energy gain of 380meV under pulsed excitation equivalent to 105 times solar concentration. However, for upconverters to be viable for solar energy harvesting, they must have high efficiency in low-light (1-sun) conditions. Engineering improved performance under device-relevant conditions requires a better understanding of the upconversion mechanisms. We synthesize core/rod/emitter complexes and demonstrate near-infrared (NIR)-to-visible upconversion photoluminescence (UCPL) in these structures with continuous wave (CW) illumination near low-light conditions. We further observe photon energy gains of 700meV (from 850nm to 575nm). To improve upconversion efficiency, we grow homogeneous absorber QDs and alloyed rods and systematically study the quantum yield using an integrating sphere to measure upconversion photoluminescence relative to a rhodamine 101 standard. We observe an order of magnitude increase in upconversion quantum efficiency. Further understanding the effect of morphology and composition on upconversion and carrier transfer mechanisms is critical to realizing improved optical performance and upconversion quantum efficiencies in these nanostructures. |
| Databáze: | OpenAIRE |
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