TY - JOUR
T1 - Mechanisms of LiF Interlayer Enhancements of Perovskite Light-Emitting Diodes
AU - Quintero-Bermudez, Rafael
AU - Kirman, Jeffrey
AU - Ma, Dongxin
AU - Sargent, Edward H.
AU - Quintero-Torres, Rafael
N1 - Funding Information:
This publication is based in part on work supported by the Ontario Research Fund Research Excellence Program and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. R.Q.-T. acknowledges the support of UNAM-DGAPA-PASPA and UNAM-DGAPA-PAPIIT, grant number IN112017.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/5/21
Y1 - 2020/5/21
N2 - The use of LiF as a thin interlayer between the electron transport layer and cathode has played a pivotal role in remarkable advances in perovskite LEDs (PeLEDs); however, the mechanism behind the effect of LiF remains to be fully understood. Here, we report a combined experimental and computational study, from which we ascribe the benefits of a LiF interlayer to the migration of dissociated Li into the cathode and dissociated F into the anode. Electronic device simulations reveal that the former improves electron injection by lowering the Schottky barrier height, while the latter reduces the barrier width. These reduce turn-on voltage and improve current density and charge balance in LEDs. We fabricate PeLEDs with and without the LiF interlayer and link these materials and electronic phenomena to the device light-current-voltage characteristics. X-ray photoelectron spectroscopy obtained in sputter profiling of PeLEDs corroborates the dissociation of LiF.
AB - The use of LiF as a thin interlayer between the electron transport layer and cathode has played a pivotal role in remarkable advances in perovskite LEDs (PeLEDs); however, the mechanism behind the effect of LiF remains to be fully understood. Here, we report a combined experimental and computational study, from which we ascribe the benefits of a LiF interlayer to the migration of dissociated Li into the cathode and dissociated F into the anode. Electronic device simulations reveal that the former improves electron injection by lowering the Schottky barrier height, while the latter reduces the barrier width. These reduce turn-on voltage and improve current density and charge balance in LEDs. We fabricate PeLEDs with and without the LiF interlayer and link these materials and electronic phenomena to the device light-current-voltage characteristics. X-ray photoelectron spectroscopy obtained in sputter profiling of PeLEDs corroborates the dissociation of LiF.
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U2 - 10.1021/acs.jpclett.0c00757
DO - 10.1021/acs.jpclett.0c00757
M3 - Article
C2 - 32374611
AN - SCOPUS:85085263743
SN - 1948-7185
VL - 11
SP - 4213
EP - 4220
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 10
ER -