The invention discloses a thermal-decay-resistant
red light Micro LED epitaxial structure and a preparation method thereof. The epitaxial structure sequentially comprises a substrate layer, an n-type buffer layer, an n-type
etching barrier layer, an n-type
ohmic contact layer, an n-type limiting layer, a
quantum well structure, a p-type spacer layer, a p-type
electron barrier layer and a p-type
ohmic contact layer from bottom to top. Wherein the
quantum well structure is formed by alternating 1-5 pairs of InGaP well
layers and three-section type p-type AlGaInP barrier
layers, and the three sections of barrier
layers adopt gradient
energy level design and are all subjected to p-type
doping; according to the invention, the problems of carrier loss and low recombination efficiency at high temperature in the prior art are solved by blocking
electron overflow through the gradient
energy level barrier and supplementing the hole concentration through p-type
doping, so that the 85 DEG C external
quantum efficiency attenuation rate is less than or equal to 10%, the service life is prolonged to more than 50,000 hours, and the process is compatible with
mass production and is suitable for the fields of display, illumination and the like.