Al- and N-polar AlN layers grown on c-plane sapphire substrates by modified flow-modulation MOCVD

In situ gravimetric monitoring of surface reactions between sapphire and NH3

“…The polarity of AlN is controlled by pre-growth treatment of the C-plane sapphire substrate in flowing NH 3 [9]. However, it is well known that H 2 is generated by the decomposition of NH 3 at high temperatures [10], and this H 2 is expected to react with the sapphire surface.…”

High-temperature growth of thick AlN layers on sapphire (0 0 0 1) substrates by solid source halide vapor-phase epitaxy

“…This value is little different from that obtained by PL measurement ($5.95 eV). Takeuchi et al[24] also showed that the band-edge emission of 5.950 eV was obtained from MOVPE-grown AlN layers on sapphire ARTICLE IN PRESS Room temperature PL profiles of AlN layers grown at various temperatures (a) and intensity ratio of the near band-edge emission (I BE ) to the broad luminescence band (I BL ) as a function of growth temperature (b). ArF excimer laser (193 nm) was used as an excitation source.…”

Theory Research on the Solar Cell Martial of GaN by a Novel Method

“…The full width at half maximum (FWHM) of (002) diffraction is correlated with the density of screw dislocations, while asymmetric (102) is sensitive to the pure edge and mixed dislocations [4]. The TD density can be calculated by the equation [5]. Where ρs is the screw dislocation density, ρe is the edge dislocation density, β(002) and β(102) are the full width at half maximum (FWHM) of (002) and (102) diffraction, while Bs and Be are Burger vector sizes of the screw (c = 0.5185 nm) and edge (a = 0.3188 nm) components.…”