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The increasing experimental and theoretical interest in two-dimensional charge carrier gases formed at the interfaces of heterostructured perovskite oxide systems has led to a demand for a deeper understanding regarding the influence of exchange–correlation functionals and associated corrections on the systems' properties. Herein, we investigate the impact of implementing additive Hubbard corrections compared to standard DFT routines using the PBEsol functional in polar NaTaO 3 /LaAlO 3 (001) superlattices. Structural analysis reveals that the qualitative assessment remains consistent regardless of the approach, with slight variations observed for the NaTaO 3 phase due to more pronounced polar distortions. Electronically, standard PBEsol fails to accurately describe the electronic structure of the superlattice below the system's critical thickness, whereas the inclusion of on-site Coulomb interactions through PBEsol+ U routines provides the correct semiconductor character of the superlattice, emphasizing the role of strong correlation effects on d and f electrons at the material's interface. Additionally, our investigation reveals the spatial charge separation in the semiconductor heterostructure, with potential implications for photocatalytic devices. This work not only contributes to demonstrate the importance of the chosen methodology when studying such systems but also sheds light on important electronic and structural properties of NaTaO 3 /LaAlO 3 (001) superlattices, enabling new avenues for future applications. [Display omitted] • NaTaO 3 /LaAlO 3 (001) superlattices were investigated using standard DFT and DFT+ U. • PBEsol calculations fail to predict the semiconductivity in the superlattices. • PBEsol+ U corrects the electronic structure according to the polar catastrophe model. • The semiconductor superlattice shows a small bandgap and spatial charge separation. [ABSTRACT FROM AUTHOR]

Researches on new 2D materials have been intensively performed over the years, strongly motivated by graphene's outstanding properties. One of the most promising classes of 2D materials under investigation is the MXenes, which are compounds obtained through chemical delamination of ternary (or quaternary) layered carbides or nitrides. MXene family possesses unique properties derived from their complex bonding (a mixture of metallic and covalent bonds) and electronic structures, atomic stacking, synthesis routes and surface terminal groups. Despite the growing interest in these materials, there is a lack of systematic information on MXenes. This manuscript aimed to review and comment the most relevant fundamental and technological aspects of MXenes, ranging from structural and electronic characteristics of these compounds, their relevant properties and potential applications and devices. The main properties and features described in the following sections, assessed by both experimental and theoretical approaches, allow a critical analysis of the current status, trends, and potentialities of MXenes, such as their use in energy related applications, electronic and photonic devices, reinforcements of composites, and biomedical applications. Image 1 [ABSTRACT FROM AUTHOR]