TY - JOUR
T1 - Internal electric fields control triplet formation in halide perovskite-sensitized photon upconverters
AU - Prashanthan, Karunanantharajah
AU - Levine, Igal
AU - Musiienko, Artem
AU - Gutierrez-Partida, Emilio
AU - Hempel, Hannes
AU - Lips, Klaus
AU - Unold, Thomas
AU - Stolterfoht, Martin
AU - Dittrich, Thomas
AU - MacQueen, Rowan W.
N1 - Publisher Copyright:
© 2023 The Author(s)
PY - 2023/4/21
Y1 - 2023/4/21
N2 - Halide perovskite-based photon upconverters utilize perovskite thin films to sensitize triplet exciton formation in a small-molecule layer, driving triplet-triplet annihilation upconversion. Despite having excellent carrier mobility, these systems suffer from inefficient triplet formation at the perovskite/annihilator interface. We studied triplet formation in formamidinium-methylammonium lead iodide/rubrene bilayers using photoluminescence and surface photovoltage methods. By studying systems constructed on glass as well as hole-selective substrates, comprising self-assembled layers of the carbazole derivative 2PACz ([2-(9H-carbazol-9-yl)ethyl]phosphonic acid) on indium-doped tin oxide, we saw how changes in the carrier dynamics induced by the hole-selective substrate perturbed triplet formation at the perovskite/rubrene interface. We propose that an internal electric field, caused by hole transfer at the perovskite/rubrene interface, strongly affects triplet exciton formation, accelerating exciton-forming electron-hole encounters at the interface but also limiting the hole density in rubrene at high excitation densities. Controlling this field is a promising path to improving triplet formation in perovskite/annihilator upconverters.
AB - Halide perovskite-based photon upconverters utilize perovskite thin films to sensitize triplet exciton formation in a small-molecule layer, driving triplet-triplet annihilation upconversion. Despite having excellent carrier mobility, these systems suffer from inefficient triplet formation at the perovskite/annihilator interface. We studied triplet formation in formamidinium-methylammonium lead iodide/rubrene bilayers using photoluminescence and surface photovoltage methods. By studying systems constructed on glass as well as hole-selective substrates, comprising self-assembled layers of the carbazole derivative 2PACz ([2-(9H-carbazol-9-yl)ethyl]phosphonic acid) on indium-doped tin oxide, we saw how changes in the carrier dynamics induced by the hole-selective substrate perturbed triplet formation at the perovskite/rubrene interface. We propose that an internal electric field, caused by hole transfer at the perovskite/rubrene interface, strongly affects triplet exciton formation, accelerating exciton-forming electron-hole encounters at the interface but also limiting the hole density in rubrene at high excitation densities. Controlling this field is a promising path to improving triplet formation in perovskite/annihilator upconverters.
KW - Materials science
KW - Nanomaterials
UR - http://www.scopus.com/inward/record.url?scp=85150339442&partnerID=8YFLogxK
U2 - 10.1016/j.isci.2023.106365
DO - 10.1016/j.isci.2023.106365
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AN - SCOPUS:85150339442
SN - 2589-0042
VL - 26
JO - iScience
JF - iScience
IS - 4
M1 - 106365
ER -