Application of modified phonon confinement model in Raman characterization of Ge nanowires

Raman spectroscopy is an attractive tool for characterization of low-dimensional materials, such as carbon nanotubes, graphene sheets or semiconductor nanowires. Phonon confinement model [1,2] was proposed to interpret Raman signal obtained from low-dimensional materials. Due to the finite-size of the nanostructures, the fundamental q$\sim $0 Raman selection rule is relaxed, allowing the contribution from phonons away from the Brillouin-zone center. In this contribution we address several unresolved issues, such as the factors within the confinement function, incorporation of crystallographic orientation, and the interplay between the temperature and the nanostructure size [3]. Application of the modified model to the interpretation of Raman signal from Ge nanowires will be discussed.\\[4pt] [1] H. Richter, et al., Solid State Commun. 39, 625 (1981).\\[0pt] [2] I. H. Campbell et al., Solid State Commun. 58, 739 (1986).\\[0pt] [3] K. Roodenko et al., Phys. Rev. B 82, 115210 (2010).