Spectral reflectance of core-shell GaN-(Al/Hf)Ox nanowires within adapted effective medium approximation

The result contained in this repository describe expanded analysis of the reflectance spectra for the bare GaN nanowires (NWs) into the core-shell GaN-(Al/Hf)Ox structures. The EMA was adapted for such structures and was used to simplify the description of their optical and structural properties. The expected increase in the neff value (the effective refractive index) with shell thickness was confirmed, with slightly higher values for HfOx shells compared to AlOx. Moreover, the fNWs values (the fill factor) obtained from reflectance spectra matched those from SEM images, demonstrating that reflectance measurements can be a noninvasive, convenient, and quick technique for analyzing the structural properties of samples on a global scale. Whats more, a proper extension of the reflectance model was presented, which accurately modeled the measurement data. Hence, based on the structural parameters of the NW ensemble, the reflectance spectra can be predicted, which is crucial for designing and fabricating GaN-based optoelectronic devices, what makes this method valuable for both theoretical optics and nanotechnology applications.