Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, Institute for Advanced Energy Materials, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Department of Chemistry, Academy for Advanced Interdisciplinary Studies, Shenzhen Engineering Research Center for Frontier Materials Synthesis at High Pressures, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong, 518055, China.
Adv Mater. 2021 Sep;33(36):e2102190. doi: 10.1002/adma.202102190. Epub 2021 Jul 26.
Solution-processed metal-based halide perovskites have taken a dominant position for perovskite optoelectronics including light emission and X-ray detection; however, the toxicity of the included heavy metals severely restricts their applications for wearable, lightweight, and transient optoelectronic devices. Here, the authors describe investigations of large (4 × 6 × 2 mm ) 3D metal-free perovskite MDABCO-NH I (MDBACO = methyl-N'-diazabicyclo[2.2.2]octonium) single crystal and its charge recombination and extraction behavior for light emission and X-ray detection. Unlike conventional 3D metal-based perovskites, this lightweight and biocompatible perovskite large crystal is processed from aqueous solution at room temperature, and can achieve both an extremely long carrier lifetime up to ≈1.03 µs and the formation of self-trapped excited states for luminescence. These features contribute to a photoluminescence quantum yield (PLQY) as high as ≈53% at room temperature and an X-ray sensitivity up to 1997 ± 80 μC Gy cm at 50 V bias (highest among all metal-free detectors). The ability to tune the perovskite band gap by modulating the structure under high pressure is also demonstrated, which opens up applications for the crystal as colored emitters. These attributes make it a molecular alternative to metal-based perovskites for biocompatible and transient optoelectronics.
溶液处理的金属卤化物钙钛矿在包括发光和 X 射线探测在内的钙钛矿光电子学中占据主导地位；然而，所包含的重金属的毒性严重限制了它们在可穿戴、轻量级和瞬态光电子器件中的应用。在这里，作者描述了对大尺寸（4×6×2mm）3D 无金属钙钛矿 MDABCO-NH I（MDBACO=甲基-N'-二氮杂双环[2.2.2]辛基）单晶及其电荷复合和提取行为的研究，用于发光和 X 射线探测。与传统的 3D 金属基钙钛矿不同，这种轻量级和生物相容的钙钛矿大晶体是由室温下的水溶液处理而成的，并且可以实现极长的载流子寿命长达≈1.03µs 和自陷激子态的形成用于发光。这些特性有助于在室温下实现高达≈53%的光致发光量子产率（PLQY）和高达 50V 偏压下的 X 射线灵敏度高达 1997±80μCGy cm（所有无金属探测器中最高）。还证明了通过在高压下调节结构来调谐钙钛矿能带隙的能力，这为该晶体作为有色发射器开辟了应用前景。这些特性使其成为生物相容和瞬态光电子学中金属基钙钛矿的分子替代品。
