Epitaxial structure for improving efficiency drop of GaN-based LED

摘要

Proposed is an epitaxial structure for improving the efficiency drop of an LED. The epitaxial structure comprises a substrate (10), and a GaN underlying layer, a superlattice stress relief layer (50), a multi-quantum well layer (60), a P-type InGaN insertion layer (70), a P-type electron blocking layer (80) and a P-shaped GaN layer (90) which are stacked in sequence on the substrate. The P-type InGaN insertion layer (70) is inserted between the last potential barrier of the multi-quantum well layer (60) and the P-type electron blocking layer (80), an In component of the P-type InGaN insertion layer (70) gradually increases from close to the multi-quantum well layer (60) to the electron blocking layer (80) and uses pulsed Mg-doping. As such, leakage of electrons to a P end can be reduced, and at the other hand, injection from a hole to an active region can be enhanced. The problem of the efficiency drop of a GaN-based LED can be solved, and the luminescence efficiency at a large current condition can be improved.