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 200 mA 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.