Multilayer graphene/ITO transparent n‐electrodes for high‐efficiency III‐nitride light‐emitting diodes

Multilayer graphene (MLG)/ITO transparent n-electrodes for high-efficiency III-nitride light-emitting diodes (LEDs) were fabricated. MLG was grown on Ni/SiO2/Si substrates using a chemical vapor deposition method and transferred to the ITO transparent n-electrodes of the LEDs. The properties were analyzed by electroluminescence measurements, Raman spectroscopy, and radiant intensity-current testing. The external quantum efficiency (EQE) was enhanced greatly by the MLG/ITO dual layers as transparent n-electrodes in LEDs. The EQE and radiant intensity at an injection current of 200mA of the LEDs with the MLG/ITO transparent n-electrodes were improved by 33 and 32%, respectively, which was attributed to the improved light extraction through the transparent ITO n-electrodes as well as the enhanced current spreading by the MLG on the ITO layer. The high transmittance and outstanding current spreading of the MLG/ITO transparent n-electrodes have great potential for advanced transparent conducting n-electrodes in optoelectronic devices. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim