Print Email Facebook Twitter A Highly Emissive Surface Layer in Mixed-Halide Multication Perovskites Title A Highly Emissive Surface Layer in Mixed-Halide Multication Perovskites Author Andaji-Garmaroudi, Zahra (Cavendish Laboratory) Abdi-Jalebi, Mojtaba (Cavendish Laboratory) Guo, Dengyang (TU Delft ChemE/Opto-electronic Materials) Macpherson, Stuart (Cavendish Laboratory) Sadhanala, Aditya (Cavendish Laboratory; University of Oxford) Tennyson, Elizabeth M. (Cavendish Laboratory) Ruggeri, Edoardo (Cavendish Laboratory) Anaya, Miguel (Cavendish Laboratory) Savenije, T.J. (TU Delft ChemE/Opto-electronic Materials) Date 2019 Abstract Mixed-halide lead perovskites have attracted significant attention in the field of photovoltaics and other optoelectronic applications due to their promising bandgap tunability and device performance. Here, the changes in photoluminescence and photoconductance of solution-processed triple-cation mixed-halide (Cs0.06MA0.15FA0.79)Pb(Br0.4I0.6)3 perovskite films (MA: methylammonium, FA: formamidinium) are studied under solar-equivalent illumination. It is found that the illumination leads to localized surface sites of iodide-rich perovskite intermixed with passivating PbI2 material. Time- and spectrally resolved photoluminescence measurements reveal that photoexcited charges efficiently transfer to the passivated iodide-rich perovskite surface layer, leading to high local carrier densities on these sites. The carriers on this surface layer therefore recombine with a high radiative efficiency, with the photoluminescence quantum efficiency of the film under solar excitation densities increasing from 3% to over 45%. At higher excitation densities, nonradiative Auger recombination starts to dominate due to the extremely high concentration of charges on the surface layer. This work reveals new insight into phase segregation of mixed-halide mixed-cation perovskites, as well as routes to highly luminescent films by controlling charge density and transfer in novel device structures. Subject halide perovskitesluminescencepassivationphotoinduced ion migrationtime-resolved spectroscopy To reference this document use: http://resolver.tudelft.nl/uuid:31338553-7a9b-47ad-ad6b-65a9b01bbf83 DOI https://doi.org/10.1002/adma.201902374 ISSN 0935-9648 Source Advanced Materials, 31 (42) Part of collection Institutional Repository Document type journal article Rights © 2019 Zahra Andaji-Garmaroudi, Mojtaba Abdi-Jalebi, Dengyang Guo, Stuart Macpherson, Aditya Sadhanala, Elizabeth M. Tennyson, Edoardo Ruggeri, Miguel Anaya, T.J. Savenije, More Authors Files PDF Andaji_Garmaroudi_et_al_2 ... erials.pdf 1.81 MB Close viewer /islandora/object/uuid:31338553-7a9b-47ad-ad6b-65a9b01bbf83/datastream/OBJ/view