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摘要:
Bright red emission (620-650 nm) from perovskite light-emitting diodes (PeLEDs) is usually achieved via a composition including both bromine and iodine anions, which results in poor performance and stability due to phase separation under operating conditions. Here a large-scale ligand-assisted reprecipitation method is devised with nonpolar solvent that enables the fabrication of CsPbI(3)nanowire clusters, emitting at 600 nm. The blue-shift of this emission relative to that of bulk CsPbI3(approximate to 700 nm) is attributed to quantum confinement in nanowires. The growth of the nanowires is along the [011] crystal direction and is vacancy driven, resulting in the healing of surface defects and thereby a high photoluminescence quantum yield of 91%. The clusters with ultralow trap density show remarkable structural and environmental stability. PeLEDs based on these clusters exhibit an external quantum efficiency of 6.2% with Commission Internationale de l'Eclairage coordinates of (0.66, 0.34), and record luminance of 13 644 cd m(-2)of red electroluminescence. The half-lifetime under an accelerated stability test is 13.5 min for an unencapsulated device in ambient conditions operating at an initial luminance of 11 500 cd m(-2), which corresponds to an estimated half-lifetime of 694 h at 100 cd m(-2)based on acceleration factor obtained by experimental testing.
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来源 :
ADVANCED FUNCTIONAL MATERIALS
ISSN: 1616-301X
年份: 2020
期: 48
卷: 30
1 9 . 0 0 0
JCR@2022
ESI学科: MATERIALS SCIENCE;
ESI高被引阀值:169