Metal-free perovskites (MFPs) have emerged as a promising material for the development of eco-friendly, non-toxic, and wearable X-ray detectors. However, the advancement of MFPs has been hindered by several significant challenges, most notably their lower absorption coefficient and susceptibility to oxidation and degradation in iodine-based detectors. To address these issues, this study proposes a novel approach involving the doping of the B-site with Cs ions. The incorporation of Cs ions prompts degeneracy in the lowest unoccupied molecular orbital (LUMO) while preserving the dominant hydrogen bonds within the structure. As a result, there is an enhancement of several physical properties, including an increase in ion migration activation energy, augmentation in X-ray absorption capacity, and an improvement in the migration rate-lifetime (μτ) product. These enhancements are facilitated by the synergistic effects of multiple factors. Ultimately, when compared with detectors based on a single B-site ion (NH₄⁺ and Cs⁺), the X-ray detector based on the HPIP-(NH₄)_0.7Cs₀.₃Br₃·H₂O single crystal demonstrates a two-fold increase in sensitivity, achieving 1661 μC Gy_air⁻¹ cm⁻², and a detection limit of 402 nGy_air⁻¹ s⁻¹. This study validates the effectiveness of the B-site Cs ion doping strategy, paving the way for the development of high-performance devices in related fields.

中文翻译：

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氢键和能带简并的协同作用增强了HPIP-(NH4)0.7Cs0.3Br3·H2O钙钛矿的X射线检测

无金属钙钛矿 (MFP) 已成为开发环保、无毒和可穿戴 X 射线探测器的有前途的材料。然而，MFP 的进步受到了几个重大挑战的阻碍，最明显的是它们在碘基探测器中吸收系数较低以及对氧化和降解的敏感性。为了解决这些问题，本研究提出了一种新方法，涉及用 Cs 离子掺杂 B 位。 Cs 离子的掺入促进了最低未占据分子轨道 (LUMO) 的简并，同时保留了结构内的主要氢键。结果，多种物理性能得到增强，包括离子迁移活化能的增加、X射线吸收能力的增强以及迁移速率-寿命（μτ）乘积的改善。这些增强是由多种因素的协同效应促进的。最终，与基于单个B位离子（NH ₄ ⁺和Cs ⁺ ）的探测器相比，基于HPIP-(NH ₄ ) _0.7 Cs ₀的X射线探测器。₃ Br ₃ ·H ₂ O单晶的灵敏度提高了两倍，达到1661 μC Gy _air ^-1 cm ^-2，检测限为402 nGy _air ^-1 s ^-1。该研究验证了B位Cs离子掺杂策略的有效性，为相关领域高性能器件的开发铺平了道路。