In this paper, investigation has been made on the electrical properties of graphene/Al contact, ZnO/Al contact and Al/graphene/ZnO contacts in detail. Al metallization is considered, and it is performed via thermal vacuum coating technique under strict monitoring of the rate of thickness of the metal. Spin coating method and shadow masking are done for depositing fabricated graphene and ZnO on the thin film. Comparative analysis has been made on the parameters like saturation current, Barrier height and ideality factors which are calculated using Schottky barrier height (SBH) method. I–V characteristics are analyzed using the key‐sight B2029A semiconductor parameter analyzer. It is seen that the ZnO/Al contact has more ideality factor nearly 0.059 and exhibits Schottky behavior. Meanwhile, maximum saturation current is obtained for Graphene/Al contact whereas maximum barrier height is for ZnO/Al contact. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.