Monte Carlo simulations of anomalous ion channeling in near-lattice-matched $\mathrm{AlInN}/\mathrm{GaN}$ bilayers allow an accurate determination of the strain state of AlInN by Rutherford backscattering or channeling. Although these strain estimates agree well with x-ray diffraction (XRD) results, XRD composition estimates are shown to have limited accuracy, due to a possible deviation from Vegard’s law, which we quantify for this alloy. As the InN fraction increases from 13% to 19%, the strain in AlInN films changes from tensile to compressive with lattice matching predicted to occur at $[\mathrm{InN}]=17.1\%$.

The authors present a detailed study of ${\mathrm{Al}}_{1-x}{\mathrm{In}}_x\mathrm{N}$ layers covering the whole composition range of $0.09<x<1$ . All layers were grown on GaN on Si(111) templates using metal-organic vapor phase epitaxy. For $0.13<x<0.32$ samples grow fully strained and without phase separation. At higher In concentrations, the crystalline quality starts to deteriorate and a transition to three-dimensional growth is observed. A comparison of their experimental data with theoretically predicted phase diagrams reveals that biaxial strain increases the stability of the alloy.

We identify a dominant light-emitting center in ion-implanted $\text{GaN}:{\text{Eu}}^{3+}$ for which the lattice damage has been completely healed, according to x-ray diffraction and Rutherford backscattering spectrometry measurements, by high-temperature, high-pressure annealing. This center is likely to be the isolated substitutional ${\text{Eu}}_{\text{Ga}}$ defect. It lacks a “subgap” excitation band and therefore has no state in the GaN band gap, shows threefold splitting of its ${{}^7\text{F}}_2$ level, with two sublevels nearly degenerate, and exhibits a long, single-exponential luminescence decay. Competing luminescent centers of GaN:Eu involve this prime center with intrinsic lattice defects, one of which may also be responsible for the GaN yellow band.

N, Ar, and Er ions were implanted into ZnO at 15 K within a large fluence range. The Rutherford backscattering technique in the channeling mode was used to study in situ the damage built-up in the Zn sublattice at 15 K. Several stages in the damage formation were observed. From the linear increase of the damage for low implantation fluences, an upper limit of the Zn displacement energy of 65 eV could be estimated for [0001] oriented ZnO. Annealing measurements below room temperature show a significant recovery of the lattice starting at temperatures between 80 and 130 K for a sample implanted with low Er fluence. Samples with higher damage levels do not reveal any damage recovery up to room temperature, pointing to the formation of stable defect complexes.