Single-wall carbon nanotubes (SWCNTs) have been combined with indium tin oxide (ITO to improve the output power of GaN-based light emitting diodes (LEDs). LEDs fabricated with the SWCNT/ITO contacts give a forward voltage of 3.61 V at 350 mA, which is slightly higher than that of LEDs with ITO-only contacts. The SWCNT/ITO and ITO-only contacts produce transmittance values of 91.5 and 94.4% at 460 nm, respectively. However, LEDs with SWCNTs show a higher output power by 60% at 20 mA compared to those without SWCNTs. Photoemission microscope analyses show that the well-dispersed SWCNT bundle efficiently serves as a current spreader. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3269189] All rights reserved.