The existence and impact of persistent ferroelectric domains in MAPbI 3

The existence and impact of persistent ferroelectric domains in MAPbI 3

TitleThe existence and impact of persistent ferroelectric domains in MAPbI 3
Publication TypeJournal Article
Year of Publication2019
AuthorsLauren M Garten, David T Moore, Sanjini U Nanayakkara, Shyam S Dwaraknath, Philip Schulz, Jake Wands, Angus Rockett, Brian Newell, Kristin A Persson, Susan Trolier-McKinstry, David S Ginley
JournalScience Advances
Volume5
Issue1
Paginationeaas9311
Date Published01/2019
Abstract

Methylammonium lead iodide (MAPbI3) exhibits exceptional photovoltaic performance, but there remains substantial controversy over the existence and impact of ferroelectricity on the photovoltaic response. We confirm ferroelectricity in MAPbI3 single crystals and demonstrate mediation of the electronic response by ferroelectric domain engineering. The ferroelectric response sharply declines above 57°C, consistent with the tetragonal-to-cubic phase transition. Concurrent band excitation piezoresponse force microscopy–contact Kelvin probe force microscopy shows that the measured response is not dominated by spurious electrostatic interactions. Large signal poling (>16 V/cm) orients the permanent polarization into large domains, which show stabilization over weeks. X-ray photoemission spectroscopy results indicate a shift of 400 meV in the binding energy of the iodine core level peaks upon poling, which is reflected in the carrier concentration results from scanning microwave impedance microscopy. The ability to control the ferroelectric response provides routes to increase device stability and photovoltaic performance through domain engineering.

DOI10.1126/sciadv.aas9311
Short TitleSci. Adv.
Refereed DesignationRefereed