Thin-film-like composite of nanocrystal

A film-shaped single-layer composite of nanocrystal, characterized in that

• the film-shaped single-layer composite of nanocrystal consists of a film-shaped single-layer connected assembly in which a plurality of nanocrystalline pieces each having a flake-shaped form and having a main surface and an end surface are connected to each other,
• the main surface of each of the plurality of nanocrystalline pieces exposed to the outside of the connected assembly is arranged so as to form gaps therebetween,
• wherein the film-shaped single-layer connected assembly includes a film-shaped connected portion including protruding nanocrystalline pieces from a surface of the film-shaped connected portion, wherein the film-shaped connected portion excluding the protruding nanocrystalline pieces is exposed to the outside of the connected assembly and has a plan view area of 1 mm2 or more,
• wherein the plurality of nanocrystalline pieces contain copper oxide;
• and
• when, in a diffraction angle (2θ) of an X-ray diffraction spectrum, a highest peak intensity at 35.0 to 36.0 degrees is taken as I1 and a highest peak intensity at 38.5 to 40.0 degrees is taken as I2, the film-shaped single-layer composite of nanocrystal has a degree of crystal orientation having a peak intensity ratio I1/I2 of 1.05 or more.