title: Light-activated photocurrent degradation and self-healing in perovskite solar cells.
abstract: Solution-processed organometallic perovskite solar cells have emerged as one of the most promising thin-film photovoltaic technology. However, a key challenge is their lack of stability over prolonged solar irradiation. Few studies have investigated the effect of light soaking on hybrid perovskites and have attributed the degradation in the optoelectronic properties to photochemical or field-assisted ion migration. Here we show that the slow photocurrent degradation in thin-film photovoltaic devices is due to the formation of light-activated meta-stable deep-level trap states. However, the devices can self-heal completely by resting them in the dark for <1 min or the degradation can be completely prevented by operating the devices at 0 °C. We investigate several physical mechanisms to explain the microscopic origin for the formation of these trap states, among which the creation of small polaronic states involving localized cooperative lattice strain and molecular orientations emerges as a credible microscopic mechanism requiring further detailed studies.
authors.affiliation: Materials Physics and Application Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Wanyi
authors.initials: W
authors.lastname: Nie
authors.affiliation: Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Blancon
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Neukirch
authors.affiliation: Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: Kannatassen
authors.initials: K
authors.lastname: Appavoo
authors.affiliation: Materials Physics and Application Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Hsinhan
authors.initials: H
authors.lastname: Tsai
authors.affiliation: Department of Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, New Jersey 08854, USA.
authors.forename: Manish
authors.initials: M
authors.lastname: Chhowalla
authors.affiliation: School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Alam
authors.affiliation: Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: Matthew Y
authors.initials: MY
authors.lastname: Sfeir
authors.affiliation: Institut des Sciences Chimiques de Rennes, ISCR UMR 6226, CNRS, Université de Rennes 1, 35042 Rennes, France.
authors.forename: Claudine
authors.identifier: 0000-0002-2017-5823
authors.initials: C
authors.lastname: Katan
authors.affiliation: Fonctions Optiques pour les Technologies de l'Information, FOTON UMR 6082, CNRS, INSA de Rennes, 35708 Rennes, France.
authors.forename: Jacky
authors.identifier: 0000-0002-4607-3390
authors.initials: J
authors.lastname: Even
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Sergei
authors.initials: S
authors.lastname: Tretiak
authors.affiliation: Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Crochet
authors.affiliation: Materials Physics and Application Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Gautam
authors.initials: G
authors.lastname: Gupta
authors.affiliation: Materials Physics and Application Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Aditya D
authors.initials: AD
authors.lastname: Mohite