Light Extraction Enhancement from GaN-based Thin-Film LEDs Grown on Silicon after Substrate Removal Using HNA Solution

One of the promising methods to obtain high optical output power from LEDs grown on Si is to eliminate the absorptive Si substrate. In this paper, we report how GaN-based thin-film LEDs grown on silicon (111) substrates by MOCVD were successfully transferred to a copper substrate by roomtemperature electroplating and how the original Si substrate was removed by HNA solution. After fabrication, the IIInitride LED thin films showed no cracks or degradation. And the light output power of LEDs after Si removal increased by ∼ 30% compared with conventional ones before the Si removal. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.