Regensburg 2022 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 30: Poster 2

HL 30.33: Poster

Thursday, September 8, 2022, 11:00–13:00, P3

Characterizing the conductive channels of 2D perovskite field-effect transistors with Kelvin probe force microscopy — •Konstantinos Bidinakis, Shuanglong Wang, Paul W.M. Blom, Wojciech Pisula, Tomasz Marszalek, and Stefan A.L. Weber — Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany

Perovskite-based field-effect transistors (FETs) are a promising class of electronic materials, which also provide a basis for understanding the lateral charge transport within perovskites. Specifically, FETs of 2D perovskite materials exhibit diminished ion migration and improved stability against moisture compared to their 3D counterparts, due to their specific structure. The performance of the transistors is strongly influenced by the nanoscale morphology of the perovskite film. We used Kelvin probe force microscopy (KPFM) to correlate the local morphology and crystallinity with the potential distribution across a bottom-gate top-contact perovskite FET channel under operating conditions. The measured potential distribution from source to drain can indicate unwanted losses, e.g. at grain boundaries or at the electrodes.

In order to increase the crystalline quality of a Sn-based perovskite film, an additive with high Lewis alkalinity is used in the precursor solution, which coordinates with the Sn cation and retards crystallization. Using KPFM, we examined devices with and without such an additive and correlated the measured potential profiles with the charge transport characteristics, as well as ion migration and behavior at the perovskite grain boundaries.