Metastable Marvels: Navigating VO2 Polymorphs for Next-Gen Electronics and Energy Solutions

VO2 polymorphs present a unique opportunity to unravel diverse electronic properties possessed by their metastable phases. A highly reproducible, single-phase, and inexpensive synthesis method is challenging for obtaining VO2 polymorphs. Recent years have witnessed some exciting success in the growth and application of a wide range of VO2 polymorphs. This comprehensive review article delves into different polymorphs, including VO2(x) (x = A, B, M, R, C, P, and D), and investigates their distinct physical attributes. The primary focus of this article centers on providing a thorough overview of the recent progress made in stabilizing VO2(A) and VO2(B) polymorphs, emphasizing the significance of the coexistence of nanodomains at the film-substrate interface in stabilizing specific metastable phases. Additionally, the review article delves into advancements in understanding the phase transition mechanism, adjusting the order parameter in resistivity, and modifying the metal-insulator transition (MIT) temperature through doping. It also summarizes the structural, optical, electronic, and interface properties of these polymorphs and highlights their potential applications in next-generation electronic devices, particularly in the fields of sensing and energy storage.