Thermoelectric materials are substances that can convert temperature differences directly into electrical energy. They work based on the principle of the Seebeck effect, where a voltage is generated when one side of the material is heated while the other side remains cool. These materials are useful in applications like power generation and cooling systems. These materials are often characterized by their thermoelectric efficiency, which is measured by a dimensionless figure of merit known as ZT. High-performance thermoelectric materials can be used in renewable energy technologies, waste heat recovery, and even in spacecraft for power generation.