Epitaxy structures
Made out of the following materials: GaN, AlInGaN, AlN, InAlGaAs, SiC, graphene.
Deposited on different substrates
Such as: bulk GaN, sapphire, SiC, Si, InP, GaAs.
More sophisticated epitaxy structures
Such as: LEDs, lasers, strained QW edge emitting lasers, HEMTs, Schottky diodes, JFETs, MISFETs, quantum dots, VCSELs, varactors, photodetectors, passive waveguides, and others.