| Autor: |
Verma, SD, Gu, Q, Sadhanala, A, Venugopalan, V, Rao, A |
| Přispěvatelé: |
Verma, SD [0000-0002-6312-9333], Sadhanala, A [0000-0003-2832-4894], Venugopalan, V [0000-0003-4701-5536], Rao, A [0000-0003-4261-0766], Apollo - University of Cambridge Repository |
| Rok vydání: |
2019 |
| Předmět: |
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| Popis: |
Low bandgap perovskites, such as mixed Pb-Sn systems, are essential to make bottom cells in all perovskite tandem photovoltaics. However, currently the fundamental dynamics of carriers in these materials are not well explored. Here we use ultrafast broadband pump-probe spectroscopy to probe the two-stage carrier cooling dynamics in CH3NH3Pb1-xSnxI3 perovskites and show that the cooling is slower than in pure Pb systems. The first stage of cooling is associated with Fröhlich interactions between carriers and metal-iodide bonds that slows down monotonically with increasing Sn content. The second stage of cooling involves the decay of optical phonon into acoustic phonons and is slowest for 60% Sn content, due to an increasing gap between the optical and acoustic phonon branches. Our results provide first insights into carrier cooling dynamics in hybrid Pb-Sn halide perovskites and pave the way for further understanding of the fundamental nature of Fröhlich interactions and the decay of optical phonons in perovskite systems. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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