Epitaxial Growth of Mosaic Single-Crystalline Cu ₃ N Films on (001) SrTiO ₃ Substrates by Mist Chemical Vapor Deposition

Mosaic single-crystalline Cu 3 N films consisting of nanometer-scale grains (on the order of tens to hundreds of nanometers in size) were epitaxially grown on (001) SrTiO 3 substrates by mist chemical vapor deposition. The growth behavior and crystallinity were compared with those of Cu 3 N films grown on (0001)α-Al 2 O 3 substrates. The use of SrTiO 3 substrates, which have the same crystal structure and a lattice constant closely matched to that of Cu 3 N, enabled the growth of single-phase Cu 3 N with a [001] orientation over a wider growth temperature range than on α-Al 2 O 3 substrates. Moreover, the use of SrTiO 3 effectively suppressed the formation of rotational domains, resulting in the growth of mosaic single-crystalline Cu 3 N films. Furthermore, X-ray rocking curve analysis revealed that the Cu 3 N films grown on SrTiO 3 substrates exhibited superior crystallinity compared to those on α-Al 2 O 3 .