Metallic delafossites (ABO2) are layered oxides with quasi-two-dimensional conduction layers. Metallic delafossites are among the most conducting materials with the in-plane conductivity comparable with that of elemental metals. In this Perspective, we will discuss basic properties and future research prospects of metallic delafossites, mainly focusing on thin films and heterostructures. We exemplify the fascinating properties of these compounds, such as high conductivity and surface polarity, and discuss how it can be utilized in thin films and heterostructures.
