Tellurium is used in thermoelectric devices, particularly in bismuth telluride alloys, for efficient conversion of heat to electricity in cooling and power generation. It is added to alloys of lead, copper, and steel to improve machinability and durability in industrial applications. In the semiconductor industry, compounds like cadmium telluride are employed in infrared detectors and solar cells due to their photoconductivity. Tellurium is also found in rewritable optical media, phase-change memory devices, and some laser materials. Additionally, it serves as a catalyst in petroleum refining and rubber vulcanization, and is used in special glasses for infrared transmission optics.