Preparation method of flexible field emission cold cathode employing pencil writing

The invention discloses a preparation method of a flexible field emission cold cathode employing pencil writing. A flat, curved or linear field emission cold cathode comprising characters and/or patterns is obtained by writing the characters and/or drawing the patterns on printing paper, filter paper or paper coated with a conductive metal film through a pencil. The method is simple and easy to operate; the flexible cold cathode material can be obtained without a transfer technology, a solvent and vacuum or high-temperature annealing; the cold cathode material can be prepared on a large area; the emission current is high in density; and the required electric field is relatively low.