复旦大学方晓生教授最新AFM：无铅钙钛矿异质结构 UVC双检测性能和紫外成像、加密光通信应用研究

紫外波段 C 光电探测器 （UVC PD） 可以将 UVC 光 （200-280 nm） 信号转换为可检测信号，因其在生物医学、通信和成像领域的广泛应用而受到广泛关注。然而，目前的研究主要集中在将 UVC 光转换为电信号或将其转换为可见光信号上。本文报道了一种基于 Ca ₂ Nb ₃ O ₁₀ 纳米片和 CsCu ₂ I ₃ 薄膜的柔性双检测 UVC PD，它可以同时将 UVC 光转换为可见光和电信号，实现对不可见 UVC 光的视觉检测。PD 表现出卓越的自供电 UVC 光（270 nm;1.87 mW cm ^-2 ）检测能力，具有 16.7 mA W ^-1 的高响应度 （R）、高的检测率 6.1 × 10 ¹¹ Jones、3789 的高开/关比以及 2.1 × 10 ⁵ 的超高 UVC/UVA （R ₂₇₀ /R ₃₆₀ ） 抑制比。双重可检测 PD 在安全通信和实时成像方面显示出巨大的应用潜力。这项工作通过材料选择和结构设计提出了一种新型的柔性 PD，从而激发了提高 UVC 光检测的便利性和实用性的新思路。

Figure 1 . a) The fabrication steps of CNO/CCI123 UV PD on PET substrate. b) XRD spectra of CNO, CCI123, and CCI325 films. c,d) SEM and AFM images of CNO nanosheets and inset of c) is the corresponding SAED pattern. e,f) SEM images of CNO and CCI123 films, respectively and the inset is their corresponding AFM images. g) Height profiles of CNO and CCI123 films. h) Absorption spectra of CNO, CCI123, and CCI325 films and the inset is the energy bandgaps of CNO, CCI123, and CCI325 films. i) Energy band alignment of CNO and CCI123.

Figure 2 . a) Optical image of CCI123 and CCI325 under 254 nm illumination. b) Optical image of CCI123 film on PET substrate and the inset is the corresponding transmission spectrum. c) Flexible CCI123 film under 254 nm illumination. d,e) PL and PLE spectra of CCI123 and CCI325, respectively. f) Illustration of relaxation mechanism of the visible emission of CCI123 and CCI325.

Figure 3 . a–c) Current- voltage curves of CCI123, CNO, and CCI123/CNO heterojunctions under dark and UV illumination. d) Current-time （I-t） curves of CCI123/CNO heterojunctions at 270 nm from 0 V to 3V. e) Responsivity of the PD with different voltage. f) Responsivity and detectivity of the PD at 0 V bias. g) I-t curves of the PD under different light intensities at 270 nm. h) Photocurrent dependent on light intensities. i) I-t curves of the PD with various bending times.

‍

Figure 4 . a–c) The confidential information under daylight, 365 nm light, and 254 nm light, respectively, (the blue dots under 254 nm light are generated by CCI325, and the yellow dots are generated by CCI123). And d) is the corresponding decoded information. e) The UVC PD under tuned UVC light and the corresponding electrical signals (in linear coordinates) f). g) The decoded information from the electrical signals.

Figure 5 . a) UVC imaging demonstration using the CCI123 and CCI325 film and the corresponding imaging results b,c). d) A single pixel (CNO/CCI123) UVC imaging system and the results e).

全文链接：https://advanced.onlinelibrary.wiley.com/doi/10.1002/adfm.202422161

上 海 昂 维 科 技 有 限 公 司 现 提 供 二 维 材 料 单 晶