Observation of Long‐Term Stable Response in MAPbBr3 Single Crystals Monitored through Displacement Currents under Varying Illumination

• Published in: Solar RRL 2022-09, Vol.6 (9), p.n/a
• Main Authors: García-Batlle, Marisé, Zia, Waqas, Aranda, Clara A., Saliba, Michael, Almora, Osbel, Guerrero, Antonio, Garcia-Belmonte, Germà
• Format: Article
• Language: English
• Subjects: direct current; halide perovskites; impedance spectroscopy; transient experiments
• ISSN: 2367-198X; 2367-198X
• DOI: 10.1002/solr.202200173

Long life of perovskite devices in working conditions remains the bottleneck for technology application. Stable charge carriers’ transport together with nonreactive contact materials contributes to the increase of the device operation time. Still, an appropriate model for transport carrier mechanisms is needed because of the complex ionic–electronic interplay. Herein, methylammonium lead bromide perovskite single crystals are used to analyze the current flowing across the perovskite sample after biasing. Two methods are performed: 1) direct measurement using an amperemeter and 2) indirect method by means of an induced potential in a reference capacitor. Because of the continuity of the current, the latest method measures direct current through the sample by monitoring displacements currents. Intriguing features are observed: the displacement currents result in stable and highly reproducible responses for long‐term biasing (≈2000 s), while the direct measurements produce larger and exponentially increasing current dependence on time. These findings highlight the nontrivial effect of contacting and measuring procedures in exploring thick perovskite electrical response. Current flowing through thick single‐crystal perovskites depends on the method used to collect it. Direct measurement of current by bias application produces large and slow exponentially raising dependence on time. Indirect method, registering an induced potential in a reference series capacitor, that monitors displacement currents results in much lower, extremely stable, and highly reproducible current responses for long‐time biasing.