Morphology-driven performance in solution-processed 2d perovskite x-ray detectors with stacked architectures

Two-dimensional (2D) hybrid perovskite thin films have emerged as promising candidates for high-performance optoelectronic devices, including ionizing radiation detectors, due to their unique layered structure, favorable charge transport properties, and compatibility with low-temperature, solution-based fabrication. In this work, we investigate the role of film morphology (specifically thickness, roughness, and grain size) on the electrical and detection performance of flexible X-ray detectors based on PEA 2 PbBr 4 (phenethylammonium lead bromide) perovskite films. Devices were fabricated using a vertical stacked architecture with solution-processed films deposited from solution by spin coating. We systematically tuned film morphology by varying spin-coating speed and precursor concentration. Our results show that while thicker films improve X-ray absorption and sensitivity due to a higher attenuation fraction, they also suffer from increased roughness and reduced charge transport efficiency. Conversely, thinner films exhibit enhanced conductivity and charge collection due to better uniformity and crystallinity, despite their lower intrinsic sensitivity. A trade-off between film compactness and detection performance was also observed when modifying the solution concentration. These findings underscore the critical importance of optimizing film morphology and device architecture to achieve high-performance, flexible perovskite-based X-ray photodetectors.