▎ 摘　　要

NOVELTY - Graphene oxide is formed on substrate, and graphene oxide is provided with white light pulse, to reduce graphene oxide. USE - Formation of reduced graphene oxide used for electronic device e.g. thin film transistor (all claimed), display device, light-emitting diode and solar cell. ADVANTAGE - The reduced graphene oxide having high electroconductivity is prepared by environmentally-friendly, fast and simple process without using reducing agent and without performing separate patterning process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for thin film transistor (50), which consists of gate electrode (120), semiconductor (140) overlapped with gate electrode, and source electrode (150) and drain electrode (160) electrically connected to semiconductor and facing each other in center of semiconductor. The source electrode and drain electrode comprise reduced graphene oxide. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of thin film transistor. Thin film transistor (100) Substrate (110) Gate electrode (120) Gate insulating layer (130) Semiconductor (140) Source electrode (150) Drain electrode (160)