Stacking textured films on lattice-mismatched transparent conducting oxides via matched Voronoi cell of oxygen sublattice.

Transparent conducting oxides are a critical component in modern (opto)electronic devices and solar energy conversion systems, and forming textured functional films on them is highly desirable for property manipulation and performance optimization. However, technologically important materials show varied crystal structures, making it difficult to establish coherent interfaces and consequently the oriented growth of these materials on transparent conducting oxides. Here, taking lattice-mismatched hexagonal α-Fe 2 O 3 and tetragonal fluorine-doped tin oxide as the example, atomic-level investigations reveal that a coherent ordered structure forms at their interface, and via an oxygen-mediated dimensional and chemical-matching manner, that is, matched Voronoi cells of oxygen sublattices, [110]-oriented α-Fe 2 O 3 films develop on fluorine-doped tin oxide. Further measurements of charge transport characteristics and photoelectronic effects highlight the importance and advantages of coherent interfaces and well-defined orientation in textured α-Fe 2 O 3 films. Textured growth of lattice-mismatched oxides, including spinel Co 3 O 4 , fluorite CeO 2 , perovskite BiFeO 3 and even halide perovskite Cs 2 AgBiBr 6 , on fluorine-doped tin oxide is also achieved, offering new opportunities to develop high-performance transparent-conducting-oxide-supported devices.