Narrowband near-infrared (NIR) detectors are key components for various modern biomedical, agricultural, astronomical sensing as well as monitoring applications. Typically, a narrowband organic photodetector (OPD) requires thick junctions or additional optical elements, which are either tedious or cost-ineffective. Here, we adopt the low-donor content strategy in our thin-film device to realize narrowband spectral features. The much-mitigated aggregation drastically improves shunt resistance and dark current while maintaining decent photocurrent. Upon further dilution, a thinner electron transporting layer can effectively shorten the transient response to reach fast speed. n-i-p and p-i-n device configurations are also compared, which exhibits drastic changes for low-donor content OPDs. The 5 wt% D:A thin-film bulk-heterojunction OPD presents an external quantum efficiency of 49.3% at 770 nm with zero bias, and a high thermal-noise calculated specific detectivity (D*) of 1.0 × 1013 Jones (7.1 × 1012 Jones based on noise spectral density) at 0 V. Such narrowband OPD also shows a fast NIR response of 530 ns/840 ns (rise/fall) when operated at 10 kHz. The results reveal the potential for low-donor-content blend in realizing narrowband photodetection.

中文翻译：

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低供体含量方法实现灵敏的窄带有机光电探测器

窄带近红外 (NIR) 探测器是各种现代生物医学、农业、天文传感以及监测应用的关键组件。通常，窄带有机光电探测器 (OPD) 需要厚结或额外的光学元件，这要么繁琐，要么成本低效。在这里，我们在薄膜器件中采用低施主含量策略来实现窄带光谱特征。大大减轻的聚集极大地改善了分流电阻和暗电流，同时保持了良好的光电流。进一步稀释后，更薄的电子传输层可以有效缩短瞬态响应，从而达到更快的速度。还比较了压区和针装置的配置，这对于低供体含量的 OPD 表现出巨大的变化。 5 wt% D:A 薄膜体异质结 OPD 在 770 nm 处零偏压下的外部量子效率为 49.3%，高热噪声计算比探测率 (D*) 为 1.0 × 1013 Jones (7.1 × 1012 Jones（基于噪声谱密度）在 0 V 下。这种窄带 OPD 在 10 kHz 下工作时还显示出 530 ns/840 ns（上升/下降）的快速 NIR 响应。结果揭示了低供体含量混合在实现窄带光电探测方面的潜力。