Morphology control and low-temperature magnetotransport in chiral 2D perovskite R-(MBA)${}_2$PbI${}_4$

Abstract

Two-dimensional chiral hybrid perovskites, such as R/S-(MBA)\textsubscript{2}PbI\textsubscript{4}, are leading candidates for realizing and studying chirality-dependent charge and spin transport. However, their prohibitive in-plane resistance has precluded the electrical characterization. Here, we overcome this bottleneck by engineering the thin-film morphology of the chiral perovskite $R{\text{-(MBA)}}_2{\text{PbI}}_4$, enabling the first robust lateral device integration. In Hall-bar geometries, we demonstrate Hall measurements under dark conditions, unambiguously identifying p-type conduction with a Hall mobility of $\sim 0.2{\text{cm}}^2{\text{V}}^{-1}{\text{s}}^{-1}$ and a carrier density of $\sim 3\times 10^{14}{\text{ cm}}^{-2}$, parameters previously inaccessible in this class of materials. Furthermore, we observe enhanced magnetoresistance along transport paths crossing grain boundaries, highlighting the strong influence of morphology on in-plane transport. This work demonstrates in-plane magnetotransport, enabling future investigations of the fundamental mechanisms of chirality-induced spin selectivity (CISS) and accelerating the integration of chiral materials into functional spintronic devices.

20 pages, 4 figures, supplemental information