High Performance of GaN-Based Light Emitting Diodes Grown on 4-in. Si(111) Substrate

We have demonstrated GaN-based light emitting diodes (LEDs) grown by metal-organic chemical vapor deposition on 4-in. Si(111) substrates. The structural property has been revealed by the measurement of X-ray diffraction. One of the full widths at half maximum of ω-scans of the GaN (0002) reflection is around 630 arcsec. Also, it can be found that the GaN epitaxial quality can be improved by increasing the thickness of n-GaN. The device properties have been evaluated through current–voltage, electroluminescence, and light output power–current measurements. As the n-GaN thickness increases from 1 to 2 µm, the light output powers of the LEDs have enhanced approximately two times under the injection current of 20 mA. Moreover, the maximum values of respective external quantum efficiency are achieved as 0.3 and 0.6%, respectively.