Polarity Control in Group-III Nitrides beyond Pragmatism

Chemical bonding in group III nitrides.

We analyze in this article the evolution of the chemical bonding in group III nitrides (MN, M = Al, Ga, In), from the N-N bond dominated small clusters to the M-N bond dominated crystals, with the aim of explaining how the strong multiple bond of N(2) is destabilized with the increase in coordination. The picture that emerges is that of a partially ionic bond in the solid state, which is also p...

Method and apparatus for producing group-III nitrides

Novel Reconstruction Mechanisms: a Comparison between Group-iii-nitrides and ”traditional” Iii-v-semiconductors

We have studied the driving forces governing reconstructions on polar GaN surfaces employing first-principles total-energy calculations. Our results reveal properties not observed for other semiconductors, as for example a strong tendency to stabilize Ga-rich surfaces. This mechanism is shown to have important consequences on various surface properties: Novel and hitherto unexpected structures ...

Dynamical and thermodynamic properties of III-nitrides

In this work, we have calculated ab initio the equation of state, the principal phonon modes, the effective charges and the temperature dependence of the specific heat for the III-Nitrides, by using the density-functional theory within the local density approximation, plane wave expansions and the pseudopotential method. A good agreement with the experiment and other calculations is obtained, w...

Pressure-stiffened Raman phonons in group III nitrides: a local bond average approach.

It has long been puzzling regarding the atomistic origin of the pressure-induced Raman optical phonon stiffening that generally follows a polynomial expression with coefficients needing physical indication. Here, we show that an extension of the bond-order-length-strength correlation mechanism and a local bond average approach to the pressure domain have led to an analytical solution to connect...