title: Spatial Distribution of Lead Iodide and Local Passivation on Organo-Lead Halide Perovskite.
abstract: We identify nanoscale spatial distribution of PbI2on the (FAPbI3)0.85(MAPbBr3)0.15perovskite thin film and investigate the local passivation effect using confocal based optical microscopy of steady state and time-resolved photoluminescence (PL). Different from a typical scanning electron microscope (SEM) morphology study, confocal based PL spectroscopy and microscopy allow researchers to map the morphologies of both perovskite and PbI2grains simultaneously, by selectively detecting their characteristic fluorescent bands using band-pass filters. In this work, we compare the perovskite samples without and with excess PbI2incorporation and unambiguously reveal PbI2distribution for the PbI2-rich sample. In addition, using the nanoscale time-resolved PL technique we show that the PbI2-rich regions exhibit longer lifetime due to suppressed defect trapping, compared to the PbI2-poor regions. The measurement on the PbI2-rich sample indicates that the passivation effect of PbI2in perovskite film is effective, especially in localized regions. Hence, this finding is important for further improvement of the solar cells by considering the strategy of excess PbI2incorporation.
authors.affiliation: Australia Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors.forename: Sheng
authors.initials: S
authors.lastname: Chen
authors.affiliation: Australia Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.|Centre for Micro-Photonics, Swinburne University of Technology , Melbourne, Victoria 3122, Australia.
authors.forename: Xiaoming
authors.identifier: http://orcid.org/0000-0001-8298-483X
authors.initials: X
authors.lastname: Wen
authors.affiliation: Australia Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors.forename: Jae S
authors.initials: JS
authors.lastname: Yun
authors.affiliation: Australia Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Huang
authors.affiliation: Australia Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors.forename: Martin
authors.initials: M
authors.lastname: Green
authors.affiliation: Division of Advanced Materials, Korea Research Institute of Chemical Technology , 141 Gajeong-Ro, Yuseong-Gu, Deajeon 305-600, South Korea.
authors.forename: Nam Joong
authors.initials: NJ
authors.lastname: Jeon
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan Metropolitan City 689-798, South Korea.
authors.forename: Woon Seok
authors.initials: WS
authors.lastname: Yang
authors.affiliation: Division of Advanced Materials, Korea Research Institute of Chemical Technology , 141 Gajeong-Ro, Yuseong-Gu, Deajeon 305-600, South Korea.
authors.forename: Jun Hong
authors.initials: JH
authors.lastname: Noh
authors.affiliation: Division of Advanced Materials, Korea Research Institute of Chemical Technology , 141 Gajeong-Ro, Yuseong-Gu, Deajeon 305-600, South Korea.
authors.forename: Jangwon
authors.initials: J
authors.lastname: Seo
authors.affiliation: Division of Advanced Materials, Korea Research Institute of Chemical Technology , 141 Gajeong-Ro, Yuseong-Gu, Deajeon 305-600, South Korea.|School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan Metropolitan City 689-798, South Korea.
authors.forename: Sang Il
authors.initials: SI
authors.lastname: Seok
authors.affiliation: Australia Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors.forename: Anita
authors.identifier: http://orcid.org/0000-0001-9849-4755
authors.initials: A
authors.lastname: Ho-Baillie
keywords: PbI2; lifetime; nanoscale; passivation; perovskite