Speaker
Description
Exposure to high doses of X-rays poses significant health risks due to their high photon energy and deep penetration, necessitating the development of highly sensitive detectors capable of operating at low photon doses for safer medical imaging. Perovskite materials have emerged as promising candidates for X-ray detection, with research evolving from organic systems (e.g., CH₃NH₃PbBr₃) to inorganic counterparts (CsPbBr₃) owing to their superior photo-, thermal-, and moisture stability.1 However, challenges such as material instability and high dark current continue to limit their practical application.2
Low-dimensional perovskites, particularly quasi-2D structures composed of inorganic slabs separated by organic cations, offer enhanced structural stability. Nevertheless, they often suffer from limited charge transport and reduced sensitivity. To address these limitations, semiconductor heterostructure engineering has emerged as an effective strategy, combining the advantages of different components to improve charge separation and transport while suppressing undesirable effects such as dark current.3
In this presentation, I will discuss the synthesis of PEA2Cs2Pb3Br10/CsPbBr3 perovskite heterostructure microcrystals (~20-40 μm) and the influence of precursor composition on the formation of distinct crystalline phases.4 Further, I will throw light on the impact of using heterostructures for X-ray detection and how their strategic use minimizes the trade-off between sensitivity and dark current. Furthermore, the structural and optical characterization of these heterostructures will be presented to elucidate the heterostructure properties. Their potential for X-ray detectors will also be demonstrated through proof-of-concept X-ray detector devices.
Compared to their individual constituents, the heterostructures achieve a high sensitivity of 18603.25 μC/Gycm2 and a low limit of detection of 18 μGy/s. This improvement is attributed to more efficient charge-carrier dynamics at the heterointerface and suppressed ion migration.
These results highlight quasi-2D/3D perovskite heterostructures as promising candidates for next-generation, high-performance X-ray detectors.
- Kim, S. et al. Recent advancements and challenges in highly stable all-inorganic perovskite solar cells. Mater. Today Electron. 10, 100127 (2024).
- Clinckemalie, L. et al. Challenges and Opportunities for CsPbBr3 Perovskites in Low- and High-Energy Radiation Detection. ACS Energy Lett. 6, 1290–1314 (2021).
- Zhang, X. et al. Solution‐Grown Large‐Sized Single‐Crystalline 2D/3D Perovskite Heterostructure for Self‐Powered Photodetection. Adv. Opt. Mater. 8, 2000311 (2020).
- Li, Q. et al. Bifunctional polymer assisted growth of crack-free thick perovskite films for flexible X-ray detection. J. Mater. Chem. C 10.1039.D6TC00075D (2026) doi:10.1039/D6TC00075D.