Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes
Heo, Jin Hyuck
Im, Sang Hyuk
American Association for the Advancement of Science
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Cho, H., Jeong, S., Park, M., Kim, Y., Wolf, C., Lee, C., Heo, J. H., et al. (2015). Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes. Science, 350 1222-1225. https://doi.org/10.1126/science.aad1818
Organic-inorganic hybrid perovskites are emerging low-cost emitters with very high color purity, but their low luminescent efficiency is a critical drawback. We boosted the current efficiency (CE) of perovskite light-emitting diodes with a simple bilayer structure to 42.9 candela per ampere, similar to the CE of phosphorescent organic light-emitting diodes, with two modifications: We prevented the formation of metallic lead (Pb) atoms that cause strong exciton quenching through a small increase in methylammonium bromide (MABr) molar proportion, and we spatially confined the exciton in uniform MAPbBr3 nanograins (average diameter = 99.7 nanometers) formed by a nanocrystal pinning process and concomitant reduction of exciton diffusion length to 67 nanometers. These changes caused substantial increases in steady-state photoluminescence intensity and efficiency of MAPbBr3 nanograin layers.
This work was partially supported by Samsung Research Funding Center of Samsung Electronics under Project Number SRFC-MA-1402-07. A.S. was partially supported by the Engineering and Physical Sciences Research Council (UK).
EPSRC (via Brunel University London) (unknown)
External DOI: https://doi.org/10.1126/science.aad1818
This record's URL: https://www.repository.cam.ac.uk/handle/1810/253633