Sputter-deposited α-MoO3 interlayers for van der Waals epitaxy and film transfer

Abstract

Abstract Integration of functional thin films onto flexible substrates is driven by the need to improve the performance and durability of flexible electronic devices. We present a van der Waals epitaxy technology that accomplishes the transfer of oxide or metal thin films via exfoliation or dissolution of sacrificial α-MoO3 layers produced by sputtering. The α-MoO3 thin films, consisting of weakly bonded two-dimensional layers, grew epitaxially on SrTiO3 (001) substrates, exhibiting mosaic domains rotated by 90°. Metallic Au films grown on the α-MoO3 were transferred by mechanical exfoliation or by dissolving the α-MoO3 in water at 45°C. Spinel-structured CoFe2O4 thin films grown on α-MoO3 layers were easily transferred to flexible substrates via mechanical exfoliation, and the magnetic anisotropy of the transferred CoFe2O4 films was modulated by bending.