▎ 摘　　要

NOVELTY - A LED-based epitaxial wafer comprises graphene sapphire substrate, aluminum nitride, u-gallium nitride, n-gallium nitride, multiple quantum well and p-gallium nitride thin film in order from bottom to top. USE - LED-based epitaxial wafer for chip of LED device (all claimed). ADVANTAGE - The LED-based epitaxial wafer has excellent thermal conductivity, uses gallium nitride film which has reduced stress and dislocation density, and provides LED chip having high power and excellent luminous efficiency of 20-50%. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the LED-based epitaxial wafer, which involves growing an aluminum nitride, u-gallium nitride, n-gallium nitride, multiple quantum well and p-gallium nitride thin film on graphene sapphire substrate.