Radiation Hardened Infrared Photodetectors

Nov 13, 2025
Earth’s geomagnetic field and trapped charged particles. A) Maximum total ionizing dose (TID) for standard IR sensing materials, along with their standard sensing regions: VIS, visible; NIR, near infrared; SWIR, shortwave infrared; MWIR, midwave infrared; LWIR, longwave infrared. B) Schematic depiction of the radiation environment for low-Earth orbit (LEO) and geosynchronous orbit (GEO) satellites.
Earth’s geomagnetic field and trapped charged particles. A) Maximum total ionizing dose (TID) for standard IR sensing materials, along with their standard sensing regions: VIS, visible; NIR, near infrared; SWIR, shortwave infrared; MWIR, midwave infrared; LWIR, longwave infrared. B) Schematic depiction of the radiation environment for low-Earth orbit (LEO) and geosynchronous orbit (GEO) satellites.

Space missions critically rely on sensors that operate throughout the near- to longwave infrared regions of the electromagnetic spectrum. These sensors capture data beyond the capabilities of traditional optical tools and sensors, critical for the detection of thermal emissions, conducting atmospheric studies, and surveillance. However, conventional NIR-LWIR detectors depend on bulky, cryogenically cooled semiconductors, making them impractical for broader space-based applications due to their high cost, size, weight, and power (C-SWaP) demands.

Here, an IR photodetector using a solution-processed narrow bandgap conjugated polymer is demonstrated. This direct bandgap photoconductor demonstrates exceptional infrared sensitivity without cooling and has minimal changes in figures-of-merit after substantial ionizing radiation exposure up to 1,000 krad – equivalent to three years in the most intense low Earth orbit (LEO). Its performance and resilience to radiation notably surpass conventional inorganic detectors, with a 7.7 and 98-fold increase in radiation hardness when compared to epitaxial mercury cadmium telluride (HgCdTe) and indium gallium arsenide (InGaAs) photodiodes, respectively, offering a more affordable, compact, and energy-efficient alternative.

This class of organic semiconductors provides a new frontier for C-SWaP optimized IR space sensing technologies, enabling the development of new spacecraft and missions with enhanced observational capabilities.

Authors

Jason D. Azoulay (Georgia Tech.); Jarrett H. Vella (AFRL)

Additional Materials

Designing Materials to Revolutionize and Engineer our Future (DMREF)