| 1. |
- Zhang, Xin, et al.
(författare)
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An Integrated Bulk and Surface Modification Strategy for Gas-Quenched Inverted Perovskite Solar Cells with Efficiencies Exceeding 22%
- 2022
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Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 6:6
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Tidskriftsartikel (refereegranskat)abstract
- Inverted perovskite solar cells (PSCs) prepared by the antisolvent method have achieved power conversion efficiencies (PCEs) of over 23%, but they are not ideal for device upscaling. In contrast, gas-quenched PSCs offer great potential for upscaling, but their performance still lags behind. Herein, the gas-quenched films through both surface and bulk modifications are upgraded. First, a novel surface modifier, benzylammonium thiocyanate, is found to allow remarkably improved surface properties, but the PCE gain is limited by the existence of longitudinally multiple grains. Thus, methylammonium chloride additive as a second modifier to realize monolithic grains is further utilized. Such an integrated strategy enables the average open-circuit voltage of the gas-quenched PSCs to increase from 1.08 to 1.15 V, leading to a champion PCE of 22.3%. Moreover, the unencapsulated device shows negligible degradation after 150 h of maximum power point operation under simulated 1 sun illumination in N2.
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| 2. |
- Ghosh, Supriya, et al.
(författare)
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Slower Auger Recombination in 12-Faceted Dodecahedron CsPbBr3 Nanocrystals
- 2023
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Ingår i: Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 14:4, s. 1066-1072
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Tidskriftsartikel (refereegranskat)abstract
- Over the past two decades, intensive research efforts have been devoted to suppressions of Auger recombination in metal-chalcogenide and perovskite nanocrystals (PNCs) for the application of photovoltaics and light emitting devices (LEDs). Here, we have explored dodecahedron cesium lead bromide perovskite nanocrystals (DNCs), which show slower Auger recombination time compared to hexahedron nanocrystals (HNCs). We investigate many-body interactions that are manifested under high excitation flux density in both NCs using ultrafast spectroscopic pump-probe measurements. We demonstrate that the Auger recombination rate due to multiexciton recombinations are lower in DNCs than in HNCs. At low and intermediate excitation density, the majority of carriers recombine through biexcitonic recombination. However, at high excitation density (>1018 cm-3) a higher number of many-body Auger process dominates over biexcitonic recombination. Compared to HNCs, high PLQY and slower Auger recombinations in DNCs are likely to be significant for the fabrication of highly efficient perovskite-based photonics and LEDs.
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