▎ 摘　　要

NOVELTY - The LED has a sapphire/silicon substrate layer (1), a p-type gallium nitride layer (2), a silver quantum dot layer (4) and a graphene layer (5) which are arranged from bottom to top portions. A side electrode (3) is provided in gallium nitride layer. A positive electrode (6) is provided on the graphene layer. The gallium nitride layer is made from p-type polysilicon material with the thickness of 2 to 10 microns. USE - Graphene/silver quantum dot/gallium-nitride LED for illumination device and display device. ADVANTAGE - The unique structure design of the LED is achieved, thus the bidirectional light emitting LED is realized. The light of several wavelengths is emitted by LED, and the LED is operated under forward and reverse bias conditions. The brightness of LED is improved, the LED is manufactured by simple process at low cost. The transmittance, conductivity and luminescent property of the LED are improved by using the graphite material. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a preparation method of graphene/silver quantum dot/gallium-nitride LED. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the graphene/silver quantum dot/gallium-nitride LED. Sapphire/silicon substrate layer (1) P-type gallium nitride layer (2) Side electrode (3) Silver quantum dot layer (4) Graphene layer (5) Positive electrode (6)