Dong Hun Kim

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 α‐MoO 3 layers produced by sputtering is presented. The α‐MoO 3 thin films, consisting of weakly bonded 2D layers, grow epitaxially on SrTiO 3 (001) substrates, exhibiting mosaic domains rotated by 90°. Metallic Au films grown on the α‐MoO 3 are transferred by mechanical exfoliation or by dissolving the α‐MoO 3 in water at 45 °C. Spinel‐structured CoFe 2 O 4 thin films grown on α‐MoO 3 layers are easily transferred to flexible substrates via mechanical exfoliation, and the magnetic anisotropy of the transferred CoFe 2 O 4 films is modulated by bending.