Figure 7From: Enhanced performance of photonic crystal GaN light-emitting diodes with graphene transparent electrodes Images of SiO 2 PC structure and SiO 2 PC and flat SiO 2 substrate. (a) The structure used to measure graphene sheet resistance on SiO2 PC structure. (b) The I to V curves of the two-layer graphene on SiO2 PC and on flat SiO2 substrate.Back to article page