Micro-Raman analysis of quantum confined crystalline germanium nanowire arrays

Crystalline germanium nanowires have been grown within the pores of tuneable hexagonal mesoporous silica matrices (HMS) using a supercritical inclusion phase technique. Micro-Raman spectroscopical analysis was performed on the Ge nanowires with diameter ranging from 20 to 85 Å. No stress-induced lattice parameter change of the Ge core was detected and the profile and shape of the Raman peak is mainly attributed to the quantum confinement of optical phonons in the Ge nanowires. The physical dimension of the scattering crystalline nanowires lead to a downshift and broadening of the first-order Raman line through a relaxation of the q ∼ 0 selection rule.