Various Optical Sapphire Applications

LED remains the dominant sapphire application. Sapphire substrates are ideal for use in LED applications due to high-temperature resistance, high strength, good electrical insulation, and low dielectric loss. Sapphire substrate in LED lighting helps prevent stray currents caused by radiation from spreading to nearby circuit elements. Its crystal structure also allows LED lights to have a wider beam angle.

GaN is the major material used for blue-light/green-light LED due to their ability to combine electrical parts and LED optical parts, increasing LED product efficiency. The GaN-based LEDs grown on the sapphire substrate have current transport due to the insulating nature of the substrate. In addition, the finite resistance of the n-type GaN buffer layer causes the p–n junction current to be nonuniform and crowds.

Silicon on sapphire (SOS) is a hetero-epitaxial process for metal-oxide-semiconductor (MOS) integrated circuit (IC) manufacturing that consists of a thin layer (typically thinner than 0.6 µm) of silicon grown on a sapphire (Al2O3) wafer. SOS is part of the silicon-on-insulator (SOI) family of CMOS (complementary MOS) technologies. Typically, high-purity artificially grown sapphire crystals are used.