AlN, or aluminum nitride, is a compound made of aluminum and nitrogen. It is known for its excellent thermal conductivity and electrical insulation properties, making it useful in various applications, including electronics and optoelectronics. AlN is often used in substrates for LEDs and power electronics due to its ability to dissipate heat effectively. In addition to its thermal and electrical properties, AlN is also chemically stable and resistant to oxidation. This makes it suitable for high-temperature applications and environments where other materials might degrade. Its unique characteristics have led to its use in ceramics and as a filler in composite materials.