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Tailoring the Energy Landscape in Quasi-2D Halide Perovskites Enables Efficient Green-Light Emission

Title
Tailoring the Energy Landscape in Quasi-2D Halide Perovskites Enables Efficient Green-Light Emission
Authors
Quan L.N.Zhao Y.García De Arquer F.P.Sabatini R.Walters G.Voznyy O.Comin R.Li Y.Fan J.Z.Tan H.Pan J.Yuan M.Bakr O.M.Lu Z.Kim D.H.Sargent E.H.
Ewha Authors
김동하
SCOPUS Author ID
김동하scopus
Issue Date
2017
Journal Title
Nano Letters
ISSN
1530-6984JCR Link
Citation
vol. 17, no. 6, pp. 3701 - 3709
Keywords
energy transferLight-emitting diodesMonte CarloPerovskitesphotoluminescence quantum yieldQuasi-2D perovskites
Publisher
American Chemical Society
Indexed
SCI; SCIE; SCOPUS WOS scopus
Abstract
Organo-metal halide perovskites are a promising platform for optoelectronic applications in view of their excellent charge-transport and bandgap tunability. However, their low photoluminescence quantum efficiencies, especially in low-excitation regimes, limit their efficiency for light emission. Consequently, perovskite light-emitting devices are operated under high injection, a regime under which the materials have so far been unstable. Here we show that, by concentrating photoexcited states into a small subpopulation of radiative domains, one can achieve a high quantum yield, even at low excitation intensities. We tailor the composition of quasi-2D perovskites to direct the energy transfer into the lowest-bandgap minority phase and to do so faster than it is lost to nonradiative centers. The new material exhibits 60% photoluminescence quantum yield at excitation intensities as low as 1.8 mW/cm2, yielding a ratio of quantum yield to excitation intensity of 0.3 cm2/mW; this represents a decrease of 2 orders of magnitude in the excitation power required to reach high efficiency compared with the best prior reports. Using this strategy, we report light-emitting diodes with external quantum efficiencies of 7.4% and a high luminescence of 8400 cd/m2. © 2017 American Chemical Society.
DOI
10.1021/acs.nanolett.7b00976
Appears in Collections:
자연과학대학 > 화학·나노과학전공 > Journal papers
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