Bionic Detectors Based on Low-Bandgap Inorganic Perovskite for Selective NIR-I Photon Detection and Imaging |
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Authors: | Fei Cao Jingde Chen Dejian Yu Shu Wang Xiaobao Xu Jiaxin Liu Zeyao Han Bo Huang Yu Gu Kwang Leong Choy Haibo Zeng |
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Affiliation: | 1. Institute of Optoelectronics & Nanomaterials, MIIT Key Laboratory of Advanced Display Materials and Devices, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094 P. R. China;2. Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, 215123 Jiangsu, P. R. China;3. Institute for Materials Discovery, University College London, Roberts Building, Malet Place, London, WC1E 7JE UK |
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Abstract: | Fluorescence imaging with photodetectors (PDs) toward near-infrared I (NIR-I) photons (700–900 nm), the so-called “optical window” in organisms, has provided an important path for tracing biological processes in vivo. With both excitation photons and fluorescence photons in this narrow range, a stringent requirement arises that the fluorescence signal should be efficiently differentiated for effective sensing, which cannot be fulfilled by common PDs with a broadband response such as Si-based PDs. In this work, delicate optical microcavities are designed to develop a series of bionic PDs with selective response to NIR-I photons, the merits of a narrowband response with a full width at half maximum (FWHM) of <50 nm, and tunability to cover the NIR-I range are highlighted. Inorganic halide perovskite CsPb0.5Sn0.5I3 is chosen as the photoactive layer with comprehensive bandgap and film engineering. As a result, these bionic PDs offer a signal/noise ratio of ≈106, a large bandwidth of 543 kHz and an ultralow detection limit of 0.33 nW. Meanwhile, the peak responsivity (R) and detectivity (D*) reach up to 270 mA W?1 and 5.4 × 1014 Jones, respectively. Finally, proof-of-concept NIR-I imaging using the PDs is demonstrated to show great promise in real-life application. |
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Keywords: | bionic photodetector fluorescence imaging halide perovskite narrowband detection NIR-I detection |
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