Year: 2016
Type: article
Abstract: Organic-inorganic perovskites such as CH3NH3PbI3 are promising materials for a variety of optoelectronic applications, with certified power conversion efficiencies in solar cells already exceeding 21%. Nevertheless, state-of-the-art films still contain performance-limiting non-radiative recombination sites and exhibit a range of complex dynamic phenomena under illumination that remain poorly understood. Here we use a unique combination of confocal photoluminescence (PL) microscopy and chemical imaging to correlate the local changes in photophysics with composition in CH3NH3PbI3 films under illumination. We demonstrate that the photo-induced 'brightening' of the perovskite PL can be attributed to an order-of-magnitude reduction in trap state density. By imaging the same regions with time-of-flight secondary-ion-mass spectrometry, we correlate this photobrightening with a net migration of iodine. Our work provides visual evidence for photo-induced halide migration in triiodide perovskites and reveals the complex interplay between charge carrier populations, electronic traps and mobile halides that collectively impact optoelectronic performance.
Source: Nature Communications
DOI: 10.1038/ncomms11683
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Awards: G1416533743, G1484699891, Graduate Research Fellowship Program (GRFP), G2639881818, G2973790809, G3207356259, G393177772, G4104599821, TAS::89 0227::TAS RECOVERY; RECOVERY ACT - CENTER FOR EXCITONICS -- EFRC; PI - MARC BALDO, G4664047395, MULTIMODAL IN SITU SCANNING PROBES FOR UNDERSTANDING MIXED ORGANIC-INORGANIC HALIDE PEROVSKITE SOLAR CELLS, G5702163051, G5878972985, Organic-inorganic perovskite hybrid tandem solar cells, Nanoengineering High-Performance Low-Cost Perovskite Solar Cells Utilising Singlet Fission Materials, TAS::89 0227::TAS RECOVERY; RECOVERY ACT - CENTER FOR EXCITONICS -- EFRC; PI - MARC BALDO, G7932826167, G8417023356, Enhanced solar light harvesting and charge transport in dye-sensitized solar cells, Cluster Ion Sources for ToF-SIMS, Meso-superstructured Hybrid Solar Cells, G952865507
OpenAlex ID: W2407336804