Effects of transparent conductive layers on characteristics of InGaN-based green resonant-cavity light-emitting diodes

InGaN-based green resonant-cavity light-emitting diodes (RCLEDs) with indium-tin oxide (ITO) and Ni/Au transparent conductive layers (TCLs) have been fabricated on Si substrates by laser lift-off and wafer bonding techniques. The RCLED structure consisted of an InGaN/GaN multiple-quantum-well active layer between the top (5 pairs) and bottom (7.5 pairs) dielectric TiO2/SiO2 distributed Bragg reflectors. It was found that the cavity mode of the RCLED with an ITO TCL shows a linewidth of 4 nm at the main emission peak at 494 nm. The electroluminescence intensity of the ITO-RCLED sample is 1.73 times higher in magnitude than that of the Ni/Au-RCLED one. It was found that the quality factor of the InGaN RCLED structure increased from 84 to 120 when the Ni/Au TCL was replaced by ITO. The improvements in both the optical output and the quality factor could be attributed to the higher optical transmittance of the ITO TCL enhancing the spontaneous emission at its resonant wavelength.