Vertical GaN-Based Light-Emitting Diodes Structure on Si(111) Substrate with Through-Holes

A novel vertical GaN-based light-emitting diode (LED) structure on a Si(111) substrate with through-holes was reported in this letter. The through-holes were formed by dry etching from the n-GaN layer to the Si substrate. Metals connecting the n-GaN layer and Si substrate were used to fill the holes. The series resistances induced by the AlN buffer layer and other interlayers were shorted by the metals filling the holes. Compared with those of the conventional LED structure, the series resistance and operating voltage at 20 mA were reduced from 26 to 22.5 Ω, and from 4.4 to 4.0 V, respectively. Light output intensity shows an increase of 29%.