Abstract
The GaN homo-junction light-emitting diodes (LEDs) with multiple-pair buffer layer (MBL) were grown by metalorganic vapor phase epitaxy on sapphire substrates. Each pair of the buffer layer consists of a 300 angstroms thick GaN nucleation layer grown at a low temperature of 525 °C and a 4 μm thick GaN epitaxial layer grown at a high temperature of 1025 °C. As compared to the conventional growth without buffer layer, the GaN LEDs with MBL will exhibit a low turn-on voltage, stronger electroluminescence intensity, and higher light output power. It is attributed to the effective reduction in the propagation of defects and dislocations near the p-n junction for the LEDs with MBL.