title: Elucidating the role of disorder and free-carrier recombination kinetics in CH3NH3PbI3 perovskite films.
abstract: Apart from broadband absorption of solar radiation, the performance of photovoltaic devices is governed by the density and mobility of photogenerated charge carriers. The latter parameters indicate how many free carriers move away from their origin, and how fast, before loss mechanisms such as carrier recombination occur. However, only lower bounds of these parameters are usually obtained. Here we independently determine both density and mobility of charge carriers in a perovskite film by the use of time-resolved terahertz spectroscopy. Our data reveal the modification of the free carrier response by strong backscattering expected from these heavily disordered perovskite films. The results for different phases and different temperatures show a change of kinetics from two-body recombination at room temperature to three-body recombination at low temperatures. Our results suggest that perovskite-based solar cells can perform well even at low temperatures as long as the three-body recombination has not become predominant.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Chan
authors.initials: C
authors.lastname: La-O-Vorakiat
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Teddy
authors.initials: T
authors.lastname: Salim
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Jeannette
authors.initials: J
authors.lastname: Kadro
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Mai-Thu
authors.initials: MT
authors.lastname: Khuc
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Haselsberger
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Huanxin
authors.initials: H
authors.lastname: Xia
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Gagik G
authors.initials: GG
authors.lastname: Gurzadyan
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Haibin
authors.initials: H
authors.lastname: Su
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Yeng Ming
authors.initials: YM
authors.lastname: Lam
authors.affiliation: 1] Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore [2] Noyes Laboratory, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Rudolph A
authors.initials: RA
authors.lastname: Marcus
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Maria-Elisabeth
authors.initials: ME
authors.lastname: Michel-Beyerle
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Elbert E M
authors.identifier: 0000000320660834
authors.initials: EE
authors.lastname: Chia