Thermal radiation sensors, also called infrared sensors, find wide applications in fields such as night vision, thermography, temperature measurement and motion detection. Most high-performance infrared sensors used in thermal imaging are bolometer type or photovoltaic type, which are generally very expensive and require additional active cooling to achieve high stability. Although there are other types of non-cooling infrared sensors, their sensitivity are generally much lower. The primary objective of this thesis is to develop a compact, low-cost, non-cooling, high-performance thermal radiation sensor that can be potentially used for large-scale thermal imaging. We have developed a novel design that adopts Si-based thermoelectric nanowires as the sensing components. Both theoretical m...[ Read more ]

Thermal radiation sensors, also called infrared sensors, find wide applications in fields such as night vision, thermography, temperature measurement and motion detection. Most high-performance infrared sensors used in thermal imaging are bolometer type or photovoltaic type, which are generally very expensive and require additional active cooling to achieve high stability. Although there are other types of non-cooling infrared sensors, their sensitivity are generally much lower. The primary objective of this thesis is to develop a compact, low-cost, non-cooling, high-performance thermal radiation sensor that can be potentially used for large-scale thermal imaging. We have developed a novel design that adopts Si-based thermoelectric nanowires as the sensing components. Both theoretical modeling and experimental fabrications/characterizations have been carried out to explore the feasibility of this design.

Analytical models have been developed to predict the theoretical performance of the designed thermal radiation sensor and they show that under favorable conditions the novel design can achieve a higher responsivity than commercial high-performance infrared sensors while maintaining a small size and comparable detectivity. The time-response behaviors of the new designs are also analyzed using numerical simulations based on finite element method. With a set of optimized parameters, the response time of the design can be shorter than 10 ms under different scenarios, making the new design suitable for real-time thermal imaging applications.

The fabrication process of the prototype thermal radiation sensor has also been developed to overcome the challenges related to nanowire patterning and integration, and a prototype free-standing sensor structure has been successfully fabricated. Various material and sensor properties are experimentally characterized. The prototype thermal radiation sensor shows that the proposed design is workable and has much room for further improvement in the future to compete against the commercial high-performance infrared sensors.