title: Ultrafast carrier dynamics in bimetallic nanostructure-enhanced methylammonium lead bromide perovskites.
abstract: In this work, we examine the impact of hybrid bimetallic Au/Ag core/shell nanostructures on the carrier dynamics of methylammonium lead tribromide (MAPbBr3) mesoporous perovskite solar cells (PSCs). Plasmon-enhanced PSCs incorporated with Au/Ag nanostructures demonstrated improved light harvesting and increased power conversion efficiency by 26% relative to reference devices. Two complementary spectral techniques, transient absorption spectroscopy (TAS) and time-resolved photoluminescence (trPL), were employed to gain a mechanistic understanding of plasmonic enhancement processes. TAS revealed a decrease in the photobleach formation time, which suggests that the nanostructures improve hot carrier thermalization to an equilibrium distribution, relieving hot phonon bottleneck in MAPbBr3perovskites. TAS also showed a decrease in carrier decay lifetimes, indicating that nanostructures enhance photoinduced carrier generation and promote efficient electron injection into TiO2prior to bulk recombination. Furthermore, nanostructure-incorporated perovskite films demonstrated quenching in steady-state PL and decreases in trPL carrier lifetimes, providing further evidence of improved carrier injection in plasmon-enhanced mesoporous PSCs.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA. rizia.bardhan@vanderbilt.edu and Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235, USA.
authors.forename: Holly F
authors.initials: HF
authors.lastname: Zarick
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Boulesbaa
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Puretzky
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA. rizia.bardhan@vanderbilt.edu and Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Talbert
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA. rizia.bardhan@vanderbilt.edu and Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235, USA.
authors.forename: Zachary R
authors.initials: ZR
authors.lastname: DeBra
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA. rizia.bardhan@vanderbilt.edu and Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235, USA.
authors.forename: Naiya
authors.initials: N
authors.lastname: Soetan
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Geohegan
authors.affiliation: Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA. rizia.bardhan@vanderbilt.edu and Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235, USA.
authors.forename: Rizia
authors.identifier: http://orcid.org/0000-0002-5854-652X
authors.initials: R
authors.lastname: Bardhan