Tunable crystallographic grain orientation and Raman fingerprints of polycrystalline SnO thin films

Abstract

In this study, (001) and (101)-orientated polycrystalline SnO films were respectively fabricated. The preferred orientation conversion was observed by modifying the stoichiometry of the SnO films. It was revealed that the O-rich and Sn-rich SnO films favor (001) and (101) grain orientations, respectively. Moreover, based on the Raman selection rule and our experimental results, the 110 cm⁻¹ Raman peak is assigned to the low-frequency E_g mode of SnO. The Raman intensity ratio between the 110 cm⁻¹ and 210 cm⁻¹ peak of SnO increases with the relative texture coefficient of the (101) grain orientation but decreases with that of the (001) one, demonstrating that the Raman characteristic information could be used as fingerprint recognition to mutually predict the crystallographic texture of SnO films.