GaN-Based LEDs Grown on HVPE Growth High Crystalline Quality Thick GaN Template

In this study, high crystalline quality 30 μm thick gallium nitride (GaN) films were grown by hydride vapor phase epitaxy (HVPE) on sapphire substrate, and the thick GaN films were used for developing high performance light-emitting diodes (LEDs). By using high-resolution X-ray diffraction, the full width at half-maximum (FWHM) of the rocking curve shows that this 30 μm thick GaN template had high crystalline quality. In addition, the transmission electron microscopy (TEM) images suggest that threading dislocation densities (TDDs) are almost free in multiple quantum wells (MQWs) for LEDs grown on 30 μm thick GaN template. Compared with conventional LEDs grown on sapphire, LEDs grown on 30 μm thick GaN template exhibit 26% enhancement of light output at 20 mA.