Impact of Device Architecture on Proton Detection Efficiency in 2D Perovskite Thick Film Detectors

ABSTRACT Hybrid organic–inorganic perovskites have emerged as promising materials for ionizing radiation detection due to their excellent optoelectronic properties, ease of performance tunability, and fabrication onto flexible substrates. In this study, we compare two device architectures, planar and stacked, for the direct detection of 5 MeV protons using thin films of 2D perovskite PEA 2 PbBr 4 (PEA = C 6 H 5 C 2 H 4 NH 3 + ). We demonstrate that the stacked configuration, with a vertical electric field across the perovskite layer, enables superior charge collection and significantly enhances detection performance compared to the lateral planar geometry. Proton irradiation experiments conducted over a wide range of fluxes (10 8 –10 1 0 H + cm − 2 s − 1 ) confirm the improved sensitivity, reproducibility, and long‐term operational stability of the stacked devices, particularly for thinner active films where morphological uniformity is higher. Additionally, stacked detectors exhibit a stable and energy‐independent response across the tested energy range (3, 4, and 5 MeV), indicating efficient charge transport and collection mechanisms, irrespective of the proton linear energy transfer. These results emphasize the key role of device geometry and highlight how the stacked configuration is a robust and scalable solution for next‐generation proton dosimeters.