Quantum Efficiency Gain in 2D Perovskite Photo and X‐Ray Detectors
Quantum Efficiency Gain in 2D Perovskite Photo and X‐Ray Detectors
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DOI：
10.1002/adom.202300847
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发表时间：
2023-07
影响因子：
9
通讯作者：
H. Tsai;L. Pan;Xinxin Li;Jinkyoung Yoo;S. Tretiak;Xuedan Ma;Lei R. Cao;W. Nie
中科院分区：
文献类型：
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作者：
H. Tsai;L. Pan;Xinxin Li;Jinkyoung Yoo;S. Tretiak;Xuedan Ma;Lei R. Cao;W. Nie
溶液法制作的钙钛矿多晶探测器是一种很有前途的低成本、可扩展的辐射成像技术，但其薄的体积限制了对高能X射线光子的传感效率。这项工作报道了二维钙钛矿薄膜光电二极管在感应可见光和X射线光子时具有探测增益。详细的功率和温度相关器件特性揭示了电荷倍增效应是观察到的高增益的原因。这是由于电子和空穴输运的差异造成的，其中电子输运被通过浅阱状态的陷阱/脱陷阱过程延迟，而空穴输运足够快，可以在满足电荷中性的情况下产生光导增益。用丁胺间隔剂制成的二维钙钛矿也被发现比用苯乙胺制成的钙钛矿表现出更大的效率增益，因为前者更有可能形成浅陷阱。薄膜二极管具有超过1 MHz的高时间响应，这是由于在薄体积上的快速电荷收集，并且该发现为未来光电子设计提供了与材料结构-功能关系相关的器件物理机制，可以提高X射线传感和昏暗光检测的效率。
The perovskite polycrystalline thin film detector fabricated by solution method is a promising low‐cost, scalable technology for radiation imaging, but its thin volume limits the sensing efficiency for high‐energy X‐ray photons. This work reports 2D perovskite thin film photo‐diodes with a detection gain when sensing visible and X‐ray photons. Detailed power and temperature‐dependent device characterizations reveal a charge multiplication effect to be responsible for the observed high gain. This is caused by a disparity in electron and hole transport, where electron transport is retarded by a trap/de‐trap process via shallow trap states, whereas the hole transport is fast enough to produce a photoconductive gain in satisfying the charge neutrality. The 2D perovskite made with butylamine spacers is also found to exhibit a larger efficiency gain than those made with phenylethylamines because of the higher likelihood of forming shallow traps in the former. The thin film diodes feature a high temporal response over 1 MHz due to the fast charge collection across a thin volume, and the discovery provides device physics mechanisms in connection to material structure‐function relationship for future optoelectronics design that can boost the efficiency of X‐ray sensing and dim light detection.