Study of efficient semipolar (11-22) InGaN green micro-light-emitting diodes on high-quality (11-22) GaN/sapphire template.

We investigated the electrical and optical performances of semipolar (11-22) InGaN green µLEDs with a size ranging from 20 × 20 µm to 100 × 100 µm, grown on a low defect density and large area (11-22) GaN template on patterned sapphire substrate. Atom probe tomography (APT) gave insights on quantum wells (QWs) thickness and indium composition and indicated that no indium clusters were observed in the QWs. The µLEDs showed a small wavelength blueshift of 5 nm, as the current density increased from 5 to 90 A/cm and exhibited a size-independent EQE of 2% by sidewall passivation using atomic-layer deposition, followed by an extremely low leakage current of ~0.