TY - JOUR
T1 - Charge Transfer Dynamics of Phase-Segregated Halide Perovskites
T2 - CH 3 NH 3 PbCl 3 and CH 3 NH 3 PbI 3 or (C 4 H 9 NH 3 ) 2 (CH 3 NH 3 ) n-1 Pb n I 3 n+1 Mixtures
AU - Cao, Duyen H.
AU - Guo, Peijun
AU - Mannodi-Kanakkithodi, Arun
AU - Wiederrecht, Gary P.
AU - Gosztola, David J.
AU - Jeon, Nari
AU - Schaller, Richard D.
AU - Chan, Maria K.Y.
AU - Martinson, Alex B.F.
PY - 2019/3/6
Y1 - 2019/3/6
N2 - Lead halide perovskites present a versatile class of solution-processable semiconductors with highly tunable bandgaps that span ultraviolet, visible, and near-infrared portions of the spectrum. We explore phase-separated chloride and iodide lead perovskite mixtures as candidate materials for intermediate band applications in future photovoltaics. X-ray diffraction and scanning electron microscopy reveal that deposition of precursor solutions across the MAPbCl 3 /MAPbI 3 composition space affords quasi-epitaxial cocrystallized films, in which the two perovskites do not alloy but instead remain phase-segregated. First-principle calculations further support the formation of an epitaxial interface and predict energy offsets in the valence band and conduction band edges that could result in intermediate energy absorption. The charge dynamics of variable mixtures of the relatively narrow bandgap (1.57 eV) MAPbI 3 perovskite and wide bandgap (3.02 eV) MAPbCl 3 are probed to map charge and energy flow direction and kinetics. Time-resolved photoluminescence and transient absorption measurements reveal charge transfer of photoexcited carriers in MAPbCl 3 to MAPbI 3 in tens of picoseconds. The rate of quenching can be further tuned by replacing MAPbI 3 with two-dimensional Ruddlesden-Popper (BA) 2 (MA) n-1 Pb n I 3n+1 (n = 3, 2, and 1) perovskites, which also remain phase-separated.
AB - Lead halide perovskites present a versatile class of solution-processable semiconductors with highly tunable bandgaps that span ultraviolet, visible, and near-infrared portions of the spectrum. We explore phase-separated chloride and iodide lead perovskite mixtures as candidate materials for intermediate band applications in future photovoltaics. X-ray diffraction and scanning electron microscopy reveal that deposition of precursor solutions across the MAPbCl 3 /MAPbI 3 composition space affords quasi-epitaxial cocrystallized films, in which the two perovskites do not alloy but instead remain phase-segregated. First-principle calculations further support the formation of an epitaxial interface and predict energy offsets in the valence band and conduction band edges that could result in intermediate energy absorption. The charge dynamics of variable mixtures of the relatively narrow bandgap (1.57 eV) MAPbI 3 perovskite and wide bandgap (3.02 eV) MAPbCl 3 are probed to map charge and energy flow direction and kinetics. Time-resolved photoluminescence and transient absorption measurements reveal charge transfer of photoexcited carriers in MAPbCl 3 to MAPbI 3 in tens of picoseconds. The rate of quenching can be further tuned by replacing MAPbI 3 with two-dimensional Ruddlesden-Popper (BA) 2 (MA) n-1 Pb n I 3n+1 (n = 3, 2, and 1) perovskites, which also remain phase-separated.
KW - 2D perovskites
KW - CH NH PbCl
KW - charge transfer dynamics
KW - halide perovskites
KW - phase-segregated
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U2 - 10.1021/acsami.8b20928
DO - 10.1021/acsami.8b20928
M3 - Article
C2 - 30789701
AN - SCOPUS:85062331364
VL - 11
SP - 9583
EP - 9593
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 9
ER -