Efficiency of bulk perovskite-sensitized upconversion: Illuminating matters
| Autor: | Jens Lackner, Sarah Wieghold, Zachary A. VanOrman, G. Ulrich Nienhaus, Karin Nienhaus, Lea Nienhaus |
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| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science Photoluminescence Physics and Astronomy (miscellaneous) business.industry Photovoltaic system 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Photon upconversion chemistry.chemical_compound chemistry Photovoltaics 0103 physical sciences Optoelectronics Triplet state 0210 nano-technology Rubrene business Order of magnitude Perovskite (structure) |
| Zdroj: | Applied Physics Letters. 118:203903 |
| ISSN: | 1077-3118 0003-6951 |
| DOI: | 10.1063/5.0050185 |
| Popis: | Photon upconversion via triplet–triplet annihilation could allow for the existing efficiency limit of single junction solar cells to be surpassed. Indeed, efficient upconversion at subsolar fluences has been realized in bulk perovskite-sensitized systems. Many questions have remained unanswered, in particular, regarding their behavior under photovoltaic operating conditions. Here, we investigate the impact of repeated and continuous illumination on bilayer perovskite/rubrene upconversion devices. We find that variations of the underlying perovskite carrier recombination dynamics greatly impact the upconversion process. Trap filling and triplet sensitization are in direct competition: more saturated trap states in the perovskite and, thus, longer underlying perovskite photoluminescence lifetimes allow for an increased number of carriers to diffuse to the perovskite/rubrene interface and undergo charge extraction to the triplet state of rubrene. As a result, the upconversion efficiency is greatly influenced by the underlying trap density: the upconverted photoluminescence intensity increases by two orders of magnitude under continuous illumination for 4 h. This shows that the upconversion efficiency is difficult to define for this system. Importantly, these results indicate that perovskite-sensitized upconversion devices exhibit peak performance under continuous illumination, which is a requirement for their successful integration into photovoltaics to help overcome the Shockley–Queisser limit in single junction solar cells. |
| Databáze: | OpenAIRE |
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