Light detection and ranging (Lidar), which utilizes scattered near-infrared (NIR) light to identify objects, has shown great potential in remote sensing, autonomous driving, robotic vision, etc. However, the intensity of the scattered NIR light is significantly reduced, placing stringent demands on the selectivity and fast response of the sensing. Even though optical filters can be used to select weak signals, the photon losses arising from additional interfaces are inevitable, thus reducing the signal-to-noise ratio (SNR). In this work, a series of organic narrowband photodetectors are constructed with tunable and selective responses from 700 to 950 nm with a minimum full-width-at-half-maximum (FWHM) of ≈30 nm. To enhance response sensitivity and speed, delicate and compact photodiode architecture is applied through comprehensive device engineering. As a result, the detectors possess a sensitive response to weak NIR light with a detection limit of 3 nW, and response rise time (τ_r) and decay time (τ_d) of ≈24 ns and ≈1.3 µs, respectively. Moreover, a proof-of-concept Lidar based on these organic photodetectors is demonstrated with a distance resolution of ≈10 cm, which further confirms the great potential in practical application.

中文翻译：

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用于弱光检测和测距的灵敏无滤波器窄带红外光电探测器

光探测和测距（Lidar）利用散射近红外（NIR）光来识别物体，在遥感、自动驾驶、机器人视觉等领域显示出巨大的潜力。然而，散射近红外光的强度显着降低，对传感的选择性和快速响应提出了严格的要求。尽管可以使用光学滤波器来选择微弱信号，但额外接口产生的光子损失是不可避免的，从而降低了信噪比（SNR）。在这项工作中，构建了一系列有机窄带光电探测器，具有 700 至 950 nm 的可调谐和选择性响应，最小半峰全宽 (FWHM) 约为 30 nm。为了提高响应灵敏度和速度，通过全面的器件工程应用了精致而紧凑的光电二极管架构。因此，探测器对弱近红外光具有灵敏的响应，检测限为 3 nW，响应上升时间 ( τ _r ) 和衰减时间 ( τ _d ) 分别为 ≈24 ns 和 ≈1.3 µs。此外，基于这些有机光电探测器的概念验证激光雷达的距离分辨率达到约10厘米，这进一步证实了其在实际应用中的巨大潜力。