Preparation of graphite and graphene thick film on AlN substrate

High-purity AlN ceramic substrate was prepared by conventional sintering in N₂ atmosphere at 1710°C for 3 hours. Measurement results of SEM, X-ray Diffraction (XRD) indicated that the AlN substrate was sintered completely, average particle size is about 1-3 μm and the porosity is very low. Graphite and graphene electrodes were obtained by simple doctor-blade coating method on AlN substrate. The samples were investigated by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope (SEM). Sheet resistance is measured by the four-probe method. Annealing at H₂ reduction atmosphere can slow down graphitized trend of graphene and protect it’s structure. The graphite electrode was applied in typical sandwich-structure DSSCs with ZnO as photoanodes, and the photoelectric conversion efficiency (η) was about 0.78%, which can be optimized and applied in DSSCs by process optimization.