Effects Of Chlorine And Fluorine On The Vibrational Properties Of Nanoporous Germanium: A Theoretical Approach

Extended Abstract Since the discovery of photoluminescence in nanoporous silicon in 1990, nanoporous semiconductors have attracted much attention due to their different properties and potential applications. Compared to porous silicon, nanoporous Germanium (pGe) has been less studied, due to its difficult synthesis that involves a bipolar electrochemical etching in hydrochloric acid, compared to the rather simple synthesis of porous Silico. However, pGe has been used in optoelectronics as photodetector, battery electrode for energy storage and backside reflector for photovoltaics. However, the theoretical characterization of this material is still scarce, this kind of investigation could be of the outmost importance in order to accelerate the development of applications using this nanostructured material, especially the determination of their vibrational properties which could indicate the stability of this material and its thermodynamic properties which are crucial for electronic and thermoelectric applications, also vibrational spectroscopies such as Raman and Infrared are intrinsically linked to the vibrational properties, by modelling these spectrums experimental investigations have a valuable resource for comparison since these are two of the most used non-destructive characterization techniques. In this work we study the vibrational properties of pGe using the first principles density functional perturbation theory and the supercell scheme [1,2 ]. The nanoporous structures are modelled by removing