title: Mobile Charge-Induced Fluorescence Intermittency in Methylammonium Lead Bromide Perovskite.
abstract: Organic-inorganic halide perovskite has emerged as a very promising material for solar cells due to its excellent photovoltaic enabling properties resulting in rapid increase in device efficiency over the last 3 years. Extensive knowledge and in-depth physical understanding in the excited state carrier dynamics are urgently required. Here we investigate the fluorescence intermittency (also known as blinking) in vapor-assisted fabricated CH3NH3PbBr3 perovskite. The evident fluorescence blinking is observed in a dense CH3NH3PbBr3 perovskite film that is composed of nanoparticles in close contact with each other. In the case of an isolated nanoparticle no fluorescence blinking is observed. The "ON" probability of fluorescence is dependent on the excitation intensity and exhibits a similar power rule to semiconductor quantum dots at higher excitation intensity. As the vapor-assisted fabricated CH3NH3PbBr3 perovskite film is a cluster of nanoparticles forming a dense film, it facilitates mobile charge migration between the nanoparticles and charge accumulation at the surface or at the boundary of the nanoparticles. This leads to enhanced Auger-like nonradiative recombination contributing to the fluorescence intermittency observed. This finding provides unique insight into the charge accumulation and migration and thus is of crucial importance for device design and improvement.
authors.affiliation: †Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia.
authors.forename: Xiaoming
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.
authors.forename: Anita
authors.initials: A
authors.lastname: Ho-Baillie
authors.affiliation: †Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia.
authors.forename: Shujuan
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.
authors.forename: Rui
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.
authors.forename: Sheng
authors.initials: S
authors.lastname: Chen
authors.affiliation: ‡Institute of Physics, Academia Sinica, Nankang, Taipei, 105, Taiwan.
authors.forename: Hsien-chen
authors.initials: HC
authors.lastname: Ko
authors.affiliation: †Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052, Australia.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Green
keywords: Fluorescence intermittency; blinking; methylammonium lead bromide; mobile charge; nanoparticle; perovskite