Evidenced piezoelectricity in pulsed laser deposited perovskite tin titanate on silicon substrate

Abstract

Perovskite-SnTiO₃ (p-SNO), due to its predicted ferroelectricity and possessing low bandgap, remains under continual investigation for the interesting fundamental and functional properties. However, reports of tetragonal p-SNO have always been controversial. Although, phase and subsequently the properties can be associated and modulated by strain engineering; the area remains largely unexplored and hence ferroelectricity as well as piezoelectricity in p-SNO are hardly testified. In the present work, major phase perovskite phase SNO film is grown by the pulsed laser deposition on silicon (100) and the strain and oxygen vacancy induced piezopotential generation and emergence of weak ferroelectricity are reported. Piezoresponse force microscopy (PFM) shows nanoscale domain reversal with a d₃₃ ~ 15 pm/V, while a minor polarisation of ~ 13 nC/cm² is recorded with incipient switching current. The relationships between the structure and the emergent functional properties are verified using finite element analysis, whereas, strain-induced piezoelectricity in this system rests as a significant finding.