Photodetectors with multiple spectral response bands have shown promise to improve imaging and communications through the switchable detection of different photon energies. However, demonstrations to date have been limited to only two bands and lack capability for fast switching in situ. Here, we exploit the band gap tunability and capability of all-perovskite tandem solar cells to demonstrate a new device concept realizing four spectral bands of response from a single multijunction device, with fast, optically controlled switching between the bands. The response to monochromatic light is highly selective and narrowband without the need for additional filters and switches to broader response bands on applying bias light. Sensitive photodetection above 6 × 10¹¹ Jones is demonstrated in all modes, with rapid switching response times of <250 ns. We demonstrate proof of principle on how the manipulation of the modular multiband detector response through light conditions enables diverse applications in optical communications with secure encryption.

中文翻译：

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具有可切换响应的可调谐多波段卤化物钙钛矿串联光电探测器

具有多个光谱响应带的光电探测器已显示出有望通过不同光子能量的可切换检测来改善成像和通信。然而，迄今为止的演示仅限于两个频段，并且缺乏现场快速切换的能力。在这里，我们利用带隙可调性和全钙钛矿串联太阳能电池的能力来展示一种新的设备概念，实现了单个多结设备的四个响应光谱带，并在波段之间进行快速、光学控制的切换。对单色光的响应具有高选择性和窄带，无需额外的滤光片，并在施加偏光时切换到更宽的响应带。6 × 10 ^{11以上的灵敏光电探测}Jones 在所有模式下都得到了展示，其快速切换响应时间小于 250 ns。我们展示了关于如何通过光照条件操纵模块化多波段检测器响应以实现具有安全加密的光通信中的各种应用的原理证明。