This invention relates to the field of
semiconductor optoelectronic device technology, specifically disclosing an epitaxial structure for a group III
nitride semiconductor light-emitting element. The epitaxial structure of this group III
nitride semiconductor light-emitting element, from bottom to top, includes a substrate, an n-type semiconductor, a
quantum well, a p-type semiconductor, and a
high electron mobility
contact layer above the p-type semiconductor. The peak position of the
high electron mobility
contact layer has a decreasing angle φ towards the
quantum well, the valley position of the
peak velocity electric field of the
high electron mobility
contact layer has an increasing angle β towards the
quantum well, the valley position of the hole mobility of the high
electron mobility contact layer has an increasing angle γ towards the
quantum well, and the valley position of the longitudinal sound velocity of the high
electron mobility contact layer has an increasing angle θ towards the
quantum well. This epitaxial structure of the group III
nitride semiconductor light-emitting element can improve hole migration efficiency and injection efficiency, and reduce
voltage variation under aging conditions.