We demonstrate the highly efficient, GaN-based, multiple-quantum-well light-emitting diodes (LEDs) grown on Si (111) substrates embedded with the AlN buffer layer using NH₃ growth interruption. Analysis of the materials by the X-ray diffraction omega scan and transmission electron microscopy revealed a remarkable improvement in the crystalline quality of the GaN layer with the AlN buffer layer using NH₃ growth interruption. This improvement originated from the decreased dislocation densities and coalescence-related defects of the GaN layer that arose from the increased Al migration time. The photoluminescence peak positions and Raman spectra indicate that the internal tensile strain of the GaN layer is effectively relaxed without generating cracks. The LEDs embedded with an AlN buffer layer using NH₃ growth interruption at 300 mA exhibited 40.9% higher light output power than that of the reference LED embedded with the AlN buffer layer without NH₃ growth interruption. These high performances are attributed to an increased radiative recombination rate owing to the low defect density and strain relaxation in the GaN epilayer.

We report the enhanced performance of near-ultraviolet (NUV) InGaN/GaN multiple quantum-well (MQW) light-emitting diodes (LEDs) with a staircase hole injector (SHI). Simulation results indicate that the internal electrostatic field in the QW of the LED-SHI is decreased owing to the reduced sheet charge density at the interface between QW and quantum barrier (QB) caused by the smaller In content difference. Additionally, the SHI structure in the QBs suppresses the ballistic or quasi-ballistic hole transport, thus enhancing efficient hole injection into the QWs. The radiative output power of an LED-SHI is increased by 25.3% at 300 mA over that of conventional LEDs with GaN QBs. The droop of internal quantum efficiency (IQE) an LED-SHI at 300 A·cm ⁻¹ is 6.1%, while the LED with GaN QBs has an IQE droop of 17.7%. The reduced IQE droop and increased radiative output power in the LED-SHI is attributed to the reduced hole overflow, increased hole injection into the MQW and the decreased electrostatic field in the MQWs. The results show that the SHI structure in the LED is promising for improved performance in high-power GaN-based NUV LEDs.