Since selective detection of multiple narrow spectral bands in the near-infrared (NIR) region still poses a fundamental challenge, we have, in this work, developed NIR photodetectors (PDs) using photon upconversion nanocrystals (UCNCs) combined with perovskite films. To conquer the relatively high pumping threshold of UCNCs, we designed a novel cascade optical field modulation strategy to boost upconversion luminescence (UCL) by cascading the superlensing effect of dielectric microlens arrays and the plasmonic effect of gold nanorods, which readily leads to a UCL enhancement by more than four orders of magnitude under weak light irradiation. By accommodating multiple optically active lanthanide ions in a core-shell-shell hierarchical architecture, developed PDs on top of this structure can detect three well-separated narrow bands in the NIR region, i.e., those centered at 808, 980, and 1540 nm. Due to the large UCL enhancement, the obtained PDs demonstrate extremely high responsivities of 30.73, 23.15, and 12.20 A W⁻¹ and detectivities of 5.36, 3.45, and 1.91 × 10¹¹ Jones for 808, 980, and 1540 nm light detection, respectively, together with short response times in the range of 80–120 ms. Moreover, we demonstrate for the first time that the response to the excitation modulation frequency of a PD can be employed to discriminate the incident light wavelength. We believe that our work provides novel insight for developing NIR PDs and that it can spur the development of other applications using upconversion nanotechnology.

由于选择性检测近红外（NIR）区域中的多个窄光谱带仍然构成一个基本挑战，因此，在这项工作中，我们开发了使用光子上转换纳米晶体（UCNC）和钙钛矿薄膜相结合的NIR光电探测器（PD）。为了克服相对较高的UCNC抽运阈值，我们设计了一种新颖的级联光场调制策略，通过级联介电微透镜阵列的超透镜效应和金纳米棒的等离激元效应来增强上转换发光（UCL），这很容易导致UCL增强在弱光照射下的光强超过四个数量级。通过在核-壳-壳层级结构中容纳多个光学活性镧系离子，在该结构顶部开发的局部放电可以检测NIR区域中三个分离良好的窄带，即以808、980和1540 nm为中心的光。由于UCL增强很大，因此获得的PD表现出30.73、23.15和12.20 A W的极高响应度^-1和5.36、3.45和1.91×10 ¹¹ Jones的检出率分别用于808、980和1540 nm的光检测，以及80-120 ms范围内的短响应时间。此外，我们首次证明对PD的激发调制频率的响应可用于区分入射光波长。我们相信，我们的工作为开发近红外PD提供了新颖的见解，并且可以促进使用上转换纳米技术开发其他应用程序。