Growth and properties of a wide-gap semiconductor InGaN

The quaternary semiconductor InGaAlN, which has a wide bandgap energy, is proposed here as a material for blue light-emitting devices. This material is a III-V system. It consists of InN, GaN and AlN with the wurtzite structure. Its bandgap energy can be selected from 2.0 to 6.2 eV. This material is promising for light-emitting devices, in particular, laser diodes. That is, a lattice-matched double-heterostructure can theoretically be constructed of this material, since large changes in bandgap energy occur for a fixed lattice constant. Epitaxial growth of single-crystal InN, the most difficult to grow of the three binary compounds of InGaAlN, has been achieved on sapphire (0001) substrates by metal organic vapor phase epitaxy. Low temperature and high V/III ratio are found to be necessary. Single-crystal InGaN has also been grown on sapphire (0001) substrates.