Mohr Johannes, Wang Yudi, Xu Xiaoyu, Wang Ruilin, Wouters Dirk J, Waser Rainer, Nag Joyeeta, Bedau Daniel
Institute of Materials in Electrical Engineering and Information Technology II, RWTH Aachen University, 52074, Aachen, Germany.
Western Digital San Jose Research Center, 5601 Great Oaks Parkway, San Jose, CA, 95119, USA.
Sci Rep. 2025 May 6;15(1):15826. doi: 10.1038/s41598-025-99892-y.
Chromium doped VO polycrystalline thin films typically consist of conductive grains separated by insulating grain boundaries. We investigate the origin of the spatially inhomogeneous resistivity in these films and find no qualitative differences between doped and undoped films, or for different oxygen stoichiometries. By a combination of conductive atomic force microscopy, high-resolution transmission electron microscopy and nanoscale elemental mapping, we show that the inhomogeneity is due to the formation of amorphous or poorly crystallized regions at the grain boundaries. Both the distribution of the dopants and the local oxygen stoichiometry appear to be very homogeneous, and therefore do not contribute to the inhomogeneous conductivity.
铬掺杂的VO多晶薄膜通常由被绝缘晶界分隔的导电晶粒组成。我们研究了这些薄膜中空间不均匀电阻率的起源，发现掺杂和未掺杂的薄膜之间，或不同氧化学计量比的薄膜之间没有质的差异。通过结合导电原子力显微镜、高分辨率透射电子显微镜和纳米级元素映射，我们表明这种不均匀性是由于在晶界处形成了非晶或结晶不良的区域。掺杂剂的分布和局部氧化学计量比似乎都非常均匀，因此不会导致电导率不均匀。
