Thermocouples: Principles and Applications in Infrared Detection

This lecture discusses the principles of thermocouples, focusing on the interaction between n-silicon and p-silicon materials. The instructor explains how thermocouples function, detailing the creation of hot and cold zones through thermal isolation. A cantilever setup is described, where a light source induces a temperature gradient, leading to charge carrier movement. The lecture covers the formation of depletion and accumulation zones in the silicon materials, resulting in electric fields that facilitate voltage generation. The concept of thermopiles is introduced, illustrating how multiple thermocouples can be arranged to enhance temperature detection. The application of thermopiles in infrared cameras is also highlighted, showcasing their use in detecting heat emissions from various sources, such as human bodies and buildings. The lecture emphasizes the practical implications of thermocouples and thermopiles in modern sensor technology, providing insights into their design and functionality.