title: Mobile Ion Induced Slow Carrier Dynamics in Organic-Inorganic Perovskite CH₃NH₃PbBr₃.
abstract: Here, we investigate photoluminescence (PL) and time-resolved photoluminescence (TRPL) in CH3NH3PbBr3 perovskite under continuous illumination, using optical and electro-optical techniques. Under continuous excitation at constant intensity, PL intensity and PL decay (carrier recombination) exhibit excitation intensity dependent reductions in the time scale of seconds to minutes. The enhanced nonradiative recombination is ascribed to light activated negative ions and their accumulation which exhibit a slow dynamics in a time scale of seconds to minutes. The observed result suggests that the organic-inorganic hybrid perovskite is a mixed electronic-ionic semiconductor. The key findings in this work suggest that ions are photoactivated or electro-activated and their accumulation at localized sites can result in a change of carrier dynamics. The findings are therefore useful for the understanding of instability of perovskite solar cells and shed light on the necessary strategies for performance improvement.
authors: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors: Sheng
authors: S
authors: Chen
authors: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors: Xiaoming
authors: X
authors: Wen
authors: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors: Rui
authors: R
authors: Sheng
authors: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors: Shujuan
authors: S
authors: Huang
authors: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors: Xiaofan
authors: X
authors: Deng
authors: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors: Martin A
authors: MA
authors: Green
authors: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors: Anita
authors: A
authors: Ho-Baillie
keywords: light soaking; mobile ions; nonradiative recombination; perovskite; slow carrier dynamics