Flexible organic optoelectronic devices simultaneously targeting mechanical conformability and fast responsivity in the near‐infrared (IR) region are a prerequisite to expand the capabilities of practical optical science and engineering for on‐skin optoelectronic applications. Here, an ultraflexible near‐IR responsive skin‐conformal photoplethysmogram sensor based on a bulk heterojunction photovoltaic active layer containing regioregular polyindacenodithiophene‐pyridyl[2,1,3]thiadiazole‐cyclopentadithiophene (PIPCP) is reported. The ultrathin (3 µm thick) photodetector exhibits unprecedented operational stability under severe mechanical deformation at a bending radius of less than 3 µm, even after more than 10³ bending cycles. Deliberate optimization of the physical dimensions of the active layer used in the device enables precise on/off switching and high device yield simultaneously. The response frequency over 1 kHz under mechanically deformed conditions facilitates conformal electronic sensors at the machine/human interface. Finally, a mechanically stretchable, flexible, and skin‐conformal photoplethysmogram (PPG) device with higher sensitivity than those of rigid devices is demonstrated, through conformal adherence to the flexuous surface of a fingerprint.

中文翻译：

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适形光体积描记器传感器的超柔近红外有机光电探测器

同时针对近红外（IR）区域中的机械一致性和快速响应性的柔性有机光电器件是扩展用于皮肤光电应用的实用光学科学和工程学能力的先决条件。在此，报道了一种基于柔性异质结光电活性传感器的超柔性近红外响应皮肤适形光体积描记器，其中该异质结光伏活性层包含区域规则的聚吲哚并二噻吩-吡啶基[2,1,3]噻二唑-环戊二噻吩（PIPCP）。超薄（3 µm厚）光电探测器即使在大于10 ³的弯曲半径下，也能在严重的机械变形下，弯曲半径小于3 µm的情况下展现出空前的操作稳定性。弯曲周期。精心优化设备中使用的有源层的物理尺寸，可以同时实现精确的开/关切换和高设备良率。在机械变形条件下，超过1 kHz的响应频率有助于在机器/人机界面处使用共形电子传感器。最后，通过共形附着在指纹的柔性表面上，证明了一种机械可拉伸，柔性和皮肤形的光电容积描记器（PPG）设备，其灵敏度高于刚性设备。