Researchers at TMOS have announced a groundbreaking development in the fight against global warming. They have created lightweight and flexible light sensors capable of imaging across a wide spectral range, from visible to infrared. This innovation is particularly suited for deployment on drones and satellites to monitor greenhouse gas emissions.
Unlike conventional cameras that rely on complex optics and flat sensor arrays, these new sensors require minimal optical components, reducing bulk, weight, and fabrication complexity. Moreover, they can detect the full spectrum of greenhouse gases without the need for cryogenic cooling, which is a common requirement for traditional infrared cameras.
The research team at TMOS has published their work on this flexible photodetector in Advanced Functional Materials. Lead author Sivacarendran Balendhran explained that conventional sensors with flat arrays necessitate multiple optical components to correct image distortion at the edges, increasing the sensor’s size and weight. However, the flexible photodetectors can enable curved focal plane arrays, mimicking the structure of the human eye and allowing for image capture with a simple lens.
The current technology for monitoring greenhouse gas emissions often requires different types of cameras to cover the broad spectral range and cryogenic cooling for certain spectral bands. In contrast, the new flexible photodetectors developed by TMOS can operate across both the infrared and visible spectra at room temperature.
Apart from their wide spectral range and compact design, these photodetectors offer simplicity and cost-effectiveness compared to traditional technologies. Commercial infrared detectors typically consist of multiple elements, including a sensor and electronic circuits for signal conversion. The sensors typically use vanadium oxide (VOx), a complex material requiring high temperatures above 450 degrees for growth.
To meet manufacturing requirements, infrared sensors are often suspended from bridge structures and enclosed in vacuum packs to isolate them from the circuitry. This approach, while effective, makes the detectors inflexible. To overcome this limitation, the TMOS research team developed a new method using VOx nanospheres grown as a powder, mixed with alcohol, and dropped onto flexible circuitry at low temperatures. This eliminates the need for bridges, vacuum packs, or complex optics.
The team has successfully demonstrated the capabilities of their detectors in a curved focal line array and plans to advance their research by manufacturing a curved focal plane array.
Chief Investigator Kenneth Crozier highlighted the significance of infrared detectors across various industries, including telecommunications, imaging, sensing, and surveillance. Integrating these detectors into flexible platforms offers numerous benefits, such as wearable sensors in the medical technology field, high-performance cameras with increased field of view and sensitivity in defense and security, and lightweight drone-operated sensors for agritech applications. The simplicity and scalability of the material synthesis and device fabrication processes make this approach a game-changer for these areas.
Source: ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS)