Emerging frontiers in oxide-based vertically aligned nanocomposites (VANs) and their device applications

Vertically Aligned Nanocomposites (VANs) are an emerging multifunctional materials platform owing to their self-assembled heterointerfaces and unique coupled functionalities. In oxide-based VANs, strong vertical strain coupling between the nanopillar and matrix increases the interfacial area, enabling physical behaviors absent in conventional single-phase counterparts. This review presents a comprehensive overview of the progress, structure–property relationships, and device applications of various oxide-based VAN systems. Prominent VAN material classes, including oxide–oxide, and, recent oxide–metal and oxide–alloy architectures, are summarized, highlighting how structural control enables ferroic coupling, ionic transport, plasmonic response, and magnetic anisotropy. The review then examines recent advances in VAN-incorporated device applications—from spintronics and resistive switching to optical sensing and flexible electronics—demonstrating the critical roles of vertical interfaces. Finally, key challenges constraining broad device integration are discussed, followed by future research directions to empower VANs for next-generation multifunctional electronic, magnetic, and photonic devices.