title: Photoluminescence characterisations of a dynamic aging process of organic-inorganic CH3NH3PbBr3 perovskite.
abstract: After unprecedented development of organic-inorganic lead halide perovskite solar cells over the past few years, one of the biggest barriers towards their commercialization is the stability of the perovskite material. It is thus important to understand the interaction between the perovskite material and oxygen and/or humidity and the associated degradation process in order to improve device and encapsulation design for better durability. Here we characterize the dynamic aging process in vapour-assisted deposited (VASP) CH3NH3PbBr3 perovskite thin films using advanced optical techniques, such as time-resolved photoluminescence and fluorescence lifetime imaging microscopy (FLIM). Our investigation reveals that the perovskite grains grow spontaneously and the larger grains are formed at room temperature in the presence of moisture and oxygen. This crystallization process leads to a higher density of defects and a shorter carrier lifetime, specifically in the larger grains. Excitation-intensity-dependent steady-state photoluminescence shows both N2 stored and aged perovskite exhibit a super-linear increase of photoluminescence intensity with increasing excitation intensity; and the larger slope in aged sample suggests a larger density of defects is generated, consistent with time-resolved PL measurements.
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: R
authors.initials: R
authors.lastname: Sheng
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: X
authors.initials: X
authors.lastname: Wen
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: S
authors.initials: S
authors.lastname: Huang
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: X
authors.initials: X
authors.lastname: Hao
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: Y
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: X
authors.initials: X
authors.lastname: Deng
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: M A
authors.initials: MA
authors.lastname: Green
authors.affiliation: Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia. x.wen@unsw.edu.au.
authors.forename: A W Y
authors.initials: AW
authors.lastname: Ho-Baillie