Thermoelectric devices are tools that convert temperature differences directly into electrical energy. They work based on the Seebeck effect, where a voltage is generated when there is a temperature gradient across two different materials. These devices can be used for power generation or cooling applications. Common examples of thermoelectric devices include thermoelectric generators and thermoelectric coolers. They are often used in remote power generation, waste heat recovery, and electronic cooling systems. Their efficiency and performance depend on the materials used, with bismuth telluride being one of the most widely used thermoelectric materials.