Unique identification of phonon modes using polarized Raman studies of SnO(001) crystals

Abstract

Stannous oxide (SnO), an exclusive p-type oxide semiconductor in the oxide family, is a source of renewed interest because of its ability to be an excellent anode material. So far, there are very few reports on the vibrational properties of SnO and controversy remains in the assignment of vibrational modes. Textured single crystals of SnO were synthesized by a one-step solvothermal method. The as-synthesized SnO crystals have a wide (001) plane, as confirmed by high resolution transmission electron microscopy images. Raman spectroscopy is used for the identification of phase as well as crystalline orientation. Moreover, a unique assignment of phonon modes in SnO is also performed using polarized Raman spectroscopic studies for different orientations around c-axis of the crystal with the incident electric field vector. Thus, a novel methodology of phonon assignment is adopted with a minimum amount of data collection for a diatomic molecule having a tetragonal symmetry with a number of symmetry elements.