Abstract:
The excitement brought by the science and technology of III-V compound
semiconductors is well described in several books1{4 and review articles5{8, published.
As shown in Fig 1.1, the nitride semiconductors AlN, GaN and InN are direct band gap
materials with energy gaps of 0.63eV (InN), 3.4 eV (GaN) and 6.2 eV (AlN). Being iso-
structural and possessing similar valance states they enable band gap engineering which
enables the formation of ternary alloys whose band gaps cover the entire range of visible
spectrum and sufficiently in the infrared and ultraviolet (UV) regions, i.e. continuously
variable from 1965 to 200 nm (0.63eV to 6.2eV). This makes them ideal candidates
for optoelectronic devices operating anywhere within this wavelength range including
for visible light emitters, UV lasers, IR-detectors, full spectrum solar cells, HEMTs etc.
