Speaker
Description
Developing flexible and lightweight detectors for real-time ionizing radiation monitoring is becoming increasingly important for applications in medicine, space, nuclear safety, and accelerator-based research. Hybrid perovskites offer an attractive route toward this goal, combining high absorption with simple and scalable solution processing. Within this material class, two-dimensional perovskites are particularly appealing due to their structural tunability, and enhanced stability compared with three-dimensional counterparts.
In particular, previous studies have demonstrated the effective use of two-dimensional perovskites for direct proton detection in planar thin-film architectures, highlighting their suitability for operation in radiation-harsh environments. [1,2] However, the conventional planar geometry imposes intrinsic limitations on charge extraction. A stacked architecture can address this issue by applying the electric field through the film thickness, thereby promoting charge collection across the full active volume. Although vertical electrode configurations have been widely explored in single-crystal perovskite detectors and are routinely used in thin-film photovoltaics, their implementation in thicker solution-processed films remains challenging. In radiation detectors, increasing the active-layer thickness can be advantageous because it enhances the interaction volume. At the same time, thicker films require high uniformity to prevent pinholes, short circuits, and local electric-field distortions, which would otherwise compromise stable detector operation.
Here, we investigate flexible stacked thick-film detectors based on two-dimensional phenethylammonium lead bromide perovskite and compare their performance with that of planar devices under direct 5 MeV proton irradiation. Devices with active-layer thicknesses of 2 and 10 µm were fabricated on plastic substrates and tested at the Laboratory of Nuclear Techniques for Environment and Cultural Heritage (INFN, Florence, Italy), using fluence rates between 10⁸ and 10¹¹ H⁺ cm⁻² s⁻¹. This comparison reveals a clear advantage of the stacked configuration, which provides a stronger and more tunable response than the planar counterpart over applied electric fields ranging from 0.05 to 0.5 V µm⁻¹. The vertical devices also display high radiation tolerance and stable operation over time, with their response retained after five months of storage in air. Overall, this work establishes vertical two-dimensional perovskite thick films as a robust platform for charged-particle detection. [3]
[1] Basiricò, Laura, et al. "Mixed 3D–2D perovskite flexible films for the direct detection of 5 MeV protons." Advanced Science 10.1 (2023): 2204815.
[2] Fratelli, Ilaria, et al. "Real‐Time Radiation Beam Monitoring by Flexible Perovskite Thin Film Arrays." Advanced Science 11.40 (2024): 2401124.
[3] Napolitano, Giulia, et al. "Impact of Device Architecture on Proton Detection Efficiency in 2D Perovskite Thick Film Detectors." Small (2026): e12236.