InGaN based light-emitting diodes （LEDs） with different electron blocking layers have been numerically investi- gated using the APSYS simulation software. It is found that the structure with a p-AlInN electron blocking layer showes improved light output power, lower current leakage, and smaller efficiency droop. Based on numerical simulation and analysis, these improvements of the electrical and optical characteristics are mainly attributed to the efficient electron blocking in the InGaN/GaN multiple quantum wells （MQWs）.
An improved GaN film with low dislocation density was grown on a C-face patterned sapphire substrate （PSS） by metalorganic chemical vapor deposition （MOCVD）. The vapor phase epitaxy starts from the regions with no etched pits and then spreads laterally to form a continuous GaN film. The properties of the GaN film have been investigated by double crystal X-ray diffraction （DCXRD）, atomic force microscopy （AFM） and photoluminescence （PL）, respectively. The full-width at half-maximum （FWHM） of the X-ray diffraction curves （XRCs） for the GaN film grown on PSS in the （0002） plane and the （1012） plane are as low as 312.80 arcsec and 298.08 acrsec, respectively. The root mean square （RMS） of the GaN film grown on PSS is 0.233 nm and the intensity of the PL peak is comparatively strong.
InGaN-based light-emitting diodes with p-GaN and p-A1GaN hole injection layers are numerically studied using the APSYS simulation software. The simulation results indicate that light-emitting diodes with p-A1GaN hole injection layers show superior optical and electrical performance, such as an increase in light output power, a reduction in current leakage and alleviation of efficiency droop. These improvements can be attributed to the p-A1GaN serving as hole injection layers, which can alleviate the band bending induced by the polarization field, thereby improving both the hole injection efficiency and the electron blocking efficiency.
