|About this Abstract
||Materials Science & Technology 2020
||Grain Boundaries, Interfaces, and Surfaces in Functional Materials: Fundamental Structure-Property-Performance Relationships
||Implications of Ferroelectricity in Perovskite Solar Cells
||Holger Roehm, Tobias Leonhard, Michael J. Hoffmann, Alexander Colsmann
|On-Site Speaker (Planned)
Methylammonium lead iodide (MAPbI3) is the archetypal semiconductor in organic metal halide solar cells. In the past four years, a controversial discussion took place about whether or not MAPbI3 is ferroelectric and if ferroelectricity can influence the solar cell performance. Yet, poling of domains in an external field could not be demonstrated in order to consolidate the discussion. In this work, we use Piezoresponse Force Microscopy to monitor ferroelectric poling of MAPbI3 thin-films across a lateral poling channel. Depending on the direction of the electric poling field relative to the domain polarization, domains can be narrowed, widened and moved within grains. Furthermore, we observe changes to the ferroelectric domain structure upon annealing of the thin-films resulting in improved solar cell performance. Our findings suggest that control of the ferroelectric domain structure in these light absorbing, semiconducting compounds may be essential in order to maximize performance of hybrid perovskite solar cells.