Sputter-Deposited -MoO₃ Interlayers for van der Waals Epitaxy and Film Transfer

Integration of functional thin films onto flexible substrates is driven by the need to improve the performance and durability of flexible electronic devices. A van der Waals epitaxy technology that accomplishes the transfer of oxide or metal thin films via exfoliation or dissolution of sacrificial alpha-MoO3 layers produced by sputtering is presented. The alpha-MoO(3 )thin films, consisting of weakly bonded 2D layers, grow epitaxially on SrTiO3 (001) substrates, exhibiting mosaic domains rotated by 90 (degrees) Metallic Au films grown on the alpha-MoO3 are transferred by mechanical exfoliation or by dissolving the alpha-MoO3 in water at 45 C-degrees. Spinel-structured CoFe2O4 thin films grown on alpha-MoO3 layers are easily transferred to flexible substrates via mechanical exfoliation, and the magnetic anisotropy of the transferred CoFe2O4 films is modulated by bending.