Monte Carlo (MC) simulations are a powerful tool for the analysis of ion-solid interactions. The MC code McChasy (Monte Carlo CHAnneling SYmulation) allows the evaluation of Rutherford Backscattering Spectrometry spectra in the Channeling mode to quantify implantation damage. The code works on common personal computers and takes into account randomly displaced atoms as well as certain types of extended defects. In this paper, we report recent improvements of the McChasy code, including a unique approach to the calculation of impact parameters between ions and target atoms in three dimensions (along with computing thermal vibrations also in three dimensions). Furthermore, the use of a rotation matrix to provide different orientations of dislocation lines and an updated model of edge dislocations were also implemented in the code. Dislocation parameters are obtained directly from high-resolution Transmission Electron Microscopy micrographs. Two case studies are presented to highlight the importance of these improvements: Ni-implanted Al was analyzed as an example of a crystal mainly containing dislocations; Er-implanted ZnO was studied, revealing the strength of MC analysis for materials containing a mixture of different defect types, namely, randomly displaced atoms and dislocations.

The effects of ¹²⁹Xe swift-heavy ion (SHI) irradiation on the optical and structural properties of InGaN/GaN multiple quantum wells (MQWs) are studied using non-destructive optical spectroscopy techniques. Through excitation wavelength-dependent μ-Raman spectroscopy, it is possible to identify the damage profile and to notice the surface region (around the first 40 nm) as the most affected one. Independent Rutherford backscattering spectrometry in channelling mode experiments corroborate this. By using resonant excitation with InGaN electronic states, it is possible to observe an increase of the A₁(LO)_InGaN phonon intensity for higher SHI energies. This is attributed to intermixing at the MQWs’ interfaces for electronic energy losses above 20 keV nm⁻¹. Photoluminescence studies reveal an intense yellow emission band (YB) with two distinct contributions: excitonic (InGaN) and deep-level defects (GaN). After irradiation, strong luminescence intensity quenching and a change in its excitation mechanisms occur. The YB is no longer excited with energy above the GaN bandgap, but instead through an excitation band (at about 2.75 eV) attributed to gallium vacancies introduced in the GaN barriers. The strong quenching of the luminescence reveals that SHI irradiation introduces detrimental defects in the structure, which may compromise its use (without additional post-implantation treatments) for obtaining more efficient green light emitters based on InGaN/GaN MQWs.