Liu Hui, Chen Tingxi, Chen Shuyan, Sun Jiayun, Kim John Jinwook, Yang Yi, Wei Guodan, Zhang Yanning, Choy Wallace C H
Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, 999077, China.
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054, China.
Adv Mater. 2025 Jul 11:e2502191. doi: 10.1002/adma.202502191.
Tin-lead binary perovskites show a very broad spectral bandwidth from ultraviolet (UV) to near-infrared (NIR) and outstanding optoelectronic properties for photodetection applications. However, the oxidation tendency of the divalent tin easily causes severe vacancies and defects, deteriorating the efficiency and stability of the device. In this work, without involving any costly synthesis of additives, a natural reducing agent of chlorogenic acid is proposed to establish a unique top-encased tri-system interlocking structure in tin-lead perovskites. Benefiting from the synergetic closed-loop interactions among functional groups of the additive with perovskites, tin-lead perovskite photodetectors (PDs) are demonstrated with improvements in energy-level alignment, antioxidation, and defect suppression and passivation. Finally, the self-powered perovskite NIR PDs present a high external quantum efficiency of ≈76%, an outstanding specific detectivity of 2 × 10 Jones at 940 nm, and a large linear dynamic range of 222 dB, along with good stability maintaining 96% of initial photocurrent after 127 days for the unencapsulated PDs storing under N atmosphere. By integrating with a 64 × 64 thin-film transistor array, the tin-lead perovskite image sensor exhibits clear and accurate imaging properties, paving the way for a wide range of high-detectivity and high-resolution imaging applications.
锡铅二元钙钛矿具有从紫外（UV）到近红外（NIR）非常宽的光谱带宽，并且在光电探测应用中具有出色的光电性能。然而，二价锡的氧化倾向容易导致严重的空位和缺陷，从而降低器件的效率和稳定性。在这项工作中，在不涉及任何昂贵添加剂合成的情况下，提出了一种天然还原剂绿原酸，以在锡铅钙钛矿中建立独特的顶部封装三系统互锁结构。受益于添加剂官能团与钙钛矿之间的协同闭环相互作用，展示了锡铅钙钛矿光电探测器（PD）在能级排列、抗氧化和缺陷抑制及钝化方面的改进。最后，自供电的钙钛矿近红外光电探测器具有约76%的高外量子效率、在940 nm处2×10琼斯的出色比探测率以及222 dB的大线性动态范围，并且对于在N气氛下储存的未封装光电探测器，在127天后仍具有良好的稳定性，保持初始光电流的96%。通过与64×64薄膜晶体管阵列集成，锡铅钙钛矿图像传感器展现出清晰准确的成像特性，为广泛的高探测率和高分辨率成像应用铺平了道路。
