Monocrystalline metal foil and manufacturing method therefor

A method for manufacturing a monocrystalline metal foil, the method comprising:

• a) a step of fixing each end of a polycrystalline metal foil by electrodes, respectively;
• and
• b) a step of heat treating the fixed polycrystalline metal foil to manufacture a monocrystalline metal foil,
• wherein the step a) further comprises a step of keeping the polycrystalline metal foil straight with a minimized stress applied to the polycrystalline metal foil by moving one or more electrodes which are fixing each end of the polycrystalline metal foil, respectively, before the step b) of heat treating the fixed polycrystalline metal foil,
• wherein the ends of the polycrystalline metal foil are opposite two edges of the polycrystalline metal foil, and a non-fixed portion, which is a region of the polycrystalline metal foil except for regions fixed by the electrodes is free of contact with solid materials, and
• wherein heat treating is performed while maintaining the polycrystalline metal foil in a straightened state by moving the one or more electrodes by a movement distance no greater than to an increased length of the polycrystalline metal foil due to thermal expansion.