Perovskite Solar Cell‐Gated Organic Electrochemical Transistors for Flexible Photodetectors with Ultrahigh Sensitivity and Fast Response

• DOI: 10.1002/adma.202207763
• Publication Date: 2022-11-14T10:00:30Z
• Authors: Jiajun Song; Guanqi Tang; Jiupeng Cao; Hong Liu; Zeyu Zhao; Sophie Griggs; Anneng Yang; Naixiang Wang; Haiyang Cheng; Chun‐Ki Liu; Iain McCulloch; Feng Yan
• Keywords: 600; 7. Clean energy

AbstractPhotodetectors (PDs) are the building block of various imaging and sensing applications. However, commercially available PDs based on crystalline inorganic semiconductors cannot meet the requirements of emerging wearable/implantable applications due to their rigidity and fragility, which creates the need for flexible devices. Here, a high‐performance flexible PD is presented by gating an organic electrochemical transistor (OECT) with a perovskite solar cell. Due to the ultrahigh transconductance of the OECT, the device demonstrates a high gain of ≈106, a fast response time of 67 µs and an ultrahigh detectivity of 6.7 × 1017 Jones to light signals under a low working voltage (≤0.6 V). Thanks to the ultrahigh sensitivity and fast response, the device can track photoplethysmogram signals and peripheral oxygen saturation under ambient light and even provide contactless remote sensing, offering a low‐power and convenient way for continuous vital signs monitoring. This work offers a novel strategy for realizing high‐performance flexible PDs that are promising for low‐power, user‐friendly and wearable optoelectronics.