A-Site Cationic Variation to Expand the Sacrificial Layer AVO3 Family Dissolving in Water

In the growing field of low-cost electronics, the epitaxy of complex oxide thin films on a Si substrate requires significant technical means. Therefore, a large attention is paid to the release of a freestanding oxide of interest from its deposition support which is then placed onto a low-cost substrate, via the etching of an intermediate sacrificial layer. The use of a sacrificial layer offers several advantages since the flexible polymer exploited for the transfer can also be fully utilized to design a flexible heterostructure. For green technology, more and more research investigations are being undertaken on these sacrificial layers etched by water. While Sr3Al2O6 and SrVO3 are archetypical examples, the need to find new materials with different lattice parameters and symmetry is critical to reach the epitaxy of numerous materials of interest. In this study, the possibilities of an A-site cationic variation in AVO3 with A = Sr and/or Ca thin films are highlighted to expand the water-soluble material's family reaching the smallest lattice parameter ever presented up to now. In addition to bring various compounds with different ageing properties to the literature, optical spectrophotometry operando characterizations to follow the chemical etching of the sacrificial layers in real-time are exploited.