The invention provides a semi-polar planar GaN-based
light emitting diode and its preparation method. The
light emitting diode comprises a substrate, an
aluminium nitride buffer layer, an undoped semi-polar planar GaN layer, a semi-polar planar GaN N-type layer, a semi-polar planar N-type InGaN insert layer, a semi-polar planar GaN / InGaN
multiple quantum well active luminescent layer, a semi-polar planar P-type AlGaN electronic
barrier layer, and a semi-polar planar P-type GaN layer. The surface of the substrate has raised graphs which are periodically arranged; the
aluminium nitride buffer layer is deposited in interval areas among the raised graphs; the undoped semi-polar planar GaN layer is manufactured on the
aluminium nitride buffer layer; there are gas areas between the undoped semi-polar planar GaN layer and the raised graphs on the surface of the substrate, thus blocking
dislocation defects from extending upwards; the semi-polar planar GaN N-type layer is manufactured on the undoped semi-polar planar GaN layer; the semi-polar planar N-type InGaN insert layer is manufactured on the semi-polar planar GaN N-type layer; the semi-polar planar GaN / InGaN
multiple quantum well active luminescent layer is manufactured on the semi-polar planar N-type InGaN insert layer; the semi-polar planar P-type AlGaN electronic
barrier layer is manufactured on the semi-polar planar GaN / InGaN
multiple quantum well active luminescent layer; and the semi-polar planar P-type GaN layer is manufactured on the semi-polar planar P-type AlGaN electronic
barrier layer.