LnCuO(S,Se,Te)monocrystalline thin film, its manufacturing method, and optical device or electronic device using the monocrystalline thin film

A method of producing an Ln1−yMyCuOX single-crystal thin film, wherein Ln is at least one selected from the group consisting of lanthanide elements and yttrium, 0<y<1, and M is at least one selected from the group consisting of Mg, Ca, Sr, Ba and Zn and X is at least one selected from the group consisting of S, Se and Te, said method comprising the steps of:

• growing a base thin film on a single-crystal substrate;
• depositing an amorphous or polycrystalline Ln1−yMyCuOX thin film on said base thin film to form a laminated film;
• enclosing said laminated film in a closed vacuum environment, and
• then annealing said laminated film at a high temperature of 500° C. or more in said vacuum environment.

A method of producing a single-crystal LnCuOX1−xX′x or Ln1−yMyCuOX1−xX′x solid-solution thin film, wherein 0<y<1, 0<x<1;

• Ln is at least one selected from the group consisting of lanthanide elements and yttrium;
• M is at least one selected from the group consisting of Mg, Ca, Sr, Ba and Zn and each of X and X′ is at least one selected from the group consisting of S, Se and Te, wherein X and X′ are different elements, said method comprising the steps of:
• preparing a substrate consisting of the LnCuOX single-crystal thin film or the Ln1−yMyCuOX single-crystal thin film;
• depositing an LnCuOX1−xX′x or Ln1−yMyCuOX1−xX′x thin film on said substrate to form a laminated film;
• enclosing said laminated film in a vacuum chamber, and
• then annealing said laminated film at a high temperature of 500° C. or more in said vacuum environment.

A method of producing an LnCuOX1−xX′x single-crystal solid solution thin film, wherein 0<x<1, Ln is at least one selected from the group consisting of lanthanide elements and yttrium, and X and X′ is at least one selected from the group consisting of S, Se and Te, wherein X and X′ are different elements, said method comprising the steps of:

• growing a base thin film on a single-crystal substrate;
• depositing an amorphous or polycrystalline LnCuOX1-xX′x solid solution thin film on said base thin film to form a laminated film;
• enclosing said laminated film in a closed vacuum environment, and
• then annealing said laminated film at a high temperature of 500° C. or more in said vacuum environment.