基于稳定二维BA₂PbBr₄的X射线探测研究

Research on X-Ray Detection Based on Stable Two-Dimensional BA₂PbBr₄

摘要: 卤化物钙钛矿因其优异的光电性能和可调谐的能带结构而备受关注，然而其环境稳定性仍是实际应用的瓶颈。具有长链有机配体的二维卤化物钙钛矿，兼具强量子限域效应、高集成性和优异的环境稳定性等优势。本研究通过降温结晶法成功制备高质量BA₂PbBr₄单晶，并构建二维BA₂PbBr₄光电探测器。在紫外探测方面，器件表现出0.035 A∙W⁻¹的响应度与极低的暗电流(2.11 × 10⁻¹² A)。更重要的是，该探测器也展现出优异的X射线探测能力，其灵敏度高达39,514 μC∙Gy_air⁻¹ cm⁻²，最低可探测剂量率为19.78 nGy_air∙s⁻¹。得益于有机配体对无机层间的有效隔离，该器件展现出卓越的环境稳定性，在空气中暴露一周后，其紫外探测性能仍能保持初始值的86.74%。本研究为开发高效稳定的钙钛矿光电子器件提供了可行的材料选择与结构设计思路。

Abstract: Halide perovskites have attracted much attention due to their excellent photoelectric properties and tunable band structure. However, their environmental stability remains a bottleneck for practical applications. Two-dimensional halide perovskites with long-chain organic ligands possess advantages such as strong quantum confinement effect, high integration, and excellent environmental stability. In this study, high-quality BA₂PbBr₄ single crystals were successfully prepared by cooling crystallization method, and a two-dimensional BA₂PbBr₄ photodetector was constructed. In the UV detection aspect, the device exhibited a response rate of 0.035 A∙W⁻¹ and extremely low dark current (2.11 × 10⁻¹² A). More importantly, this detector also demonstrated excellent X-ray detection capability, with a sensitivity of up to 39,514 μC∙Gy_air⁻¹ cm⁻² and a minimum detectable dose rate of 19.78 nGy_air∙s⁻¹. Thanks to the effective isolation of the inorganic layers by the organic ligands, this device exhibits outstanding environmental stability. After being exposed to air for one week, its UV detection performance still maintained 86.74% of the initial value. This study provides feasible material selection and structural design ideas for the development of efficient and stable perovskite photonic devices.