Design strategies and insights of flexible infrared optoelectronic sensors

Infrared optoelectronic sensing is the core of many critical applications such as night vision, health and medication, military, space exploration, etc. Further including mechanical flexibility as a new dimension enables novel features of adaptability and conformability, promising for developing next-generation optoelectronic sensory applications toward reduced size, weight, price, power consumption, and enhanced performance (SWaP³). However, in this emerging research frontier, challenges persist in simultaneously achieving high infrared response and good mechanical deformability in devices and integrated systems. Therefore, we perform a comprehensive review of the design strategies and insights of flexible infrared optoelectronic sensors, including the fundamentals of infrared photodetectors, selection of materials and device architectures, fabrication techniques and design strategies, and the discussion of architectural and functional integration towards applications in wearable optoelectronics and advanced image sensing. Finally, this article offers insights into future directions to practically realize the ultra-high performance and smart sensors enabled by infrared-sensitive materials, covering challenges in materials development and device micro-/nanofabrication. Benchmarks for scaling these techniques across fabrication, performance, and integration are presented, alongside perspectives on potential applications in medication and health, biomimetic vision, and neuromorphic sensory systems, etc.