华中科技大学牛广达团队研究出用于超灵敏硬x射线探测的高密度后钙钛矿。该项研究成果发表在2025年3月6日出版的《德国应用化学》上。

半导体的密度特性在辐射探测、电子设备和航空航天技术等应用中起着至关重要的作用。

然而，控制半导体的密度往往会导致其电子结构的重大改变，这可能导致其原有的半导体特性的损失。钙钛矿半导体以其优异的载流子输运特性而闻名，但由于其相对较低的密度和松散的原子包装，在硬x射线检测中面临限制。

本研究探索了一系列密度超过5g/cm³的后钙钛矿半导体。通过八面体的边面共享连通性和金属离子与硫族离子之间的强极化来实现。这些致密材料在保持半导体特性的同时表现出优异的电输运特性。当应用于硬x射线检测时，与最重的3D CsPbI₃钙钛矿和0D Cs₃Bi₂I₉钙钛矿相比，后钙钛矿材料表现出更好的衰减截面。BiCuSCl₂后钙钛矿探测器的灵敏度为4126 μC Gyair^-1 cm^-2，最小检出限为4.3 μC Gyair^-1。增强的密度也减轻了离子迁移，确保了优异的电稳定性。这些发现强调了后钙钛矿半导体在先进光电和辐射探测应用中的潜力。

附：英文原文

Title: High- Density Post-Perovskite for Ultra-Sensitive Hard X-ray Detection

Author: Mengling Xia, Yuzhu Li, Yinsheng Xu, Guangda Niu

Issue&Volume: 2025-03-06

Abstract: The density properties of semiconductors play a crucial role in applications such as radiation detection, electronic devices, and aerospace technologies. However, controlling the density of semiconductors often leads to significant alterations in their electronic structure, which can result in the loss of their original semiconductor properties. Perovskite semiconductors, known for their excellent carrier transport properties, face limitations in hard X-ray detection due to their relatively low density and loos atomic packing. This study explores a series of post-perovskite semiconductors with densities exceeding 5 g cm3, achieved through edge- and face-sharing connectivity of octahedra and strong polarization between metal and chalcogenide ions. These dense materials retain semiconductor properties while exhibiting superior electrical transport characteristics. When applied to hard X-ray detection, the post-perovskite materials demonstrated superior attenuation cross-sections compared to the heaviest 3D CsPbI3 perovskite and 0D Cs3Bi2I9 perovskite. Specifically, the BiCuSCl2 post-perovskite detector exhibited a high sensitivity of 4126 μC Gyair-1 cm-2 and a minimum detection limit of 4.3 nGyair s-1. The enhanced density also mitigates ionic migration, ensuring excellent electrical stability. These findings underscore the potential of post-perovskite semiconductors for advanced optoelectronic and radiation detection applications.

DOI: 10.1002/anie.202425448

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202425448