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Quantum and Dielectric Confinement Effects in Lower-Dimensional Hybrid Perovskite Semiconductors
摘要： Hybrid halide perovskites are now superstar materials leading the field of low-cost thin film photovoltaics technologies. Following the surge for more efficient and stable 3D bulk alloys, multilayered halide perovskites and colloidal perovskite nanostructures appeared in 2016 as viable alternative solutions to this challenge, largely exceeding the original proof of concept made in 2009 and 2014, respectively. This triggered renewed interest in lower-dimensional hybrid halide perovskites and at the same time increasingly more numerous and differentiated applications. The present paper is a review of the past and present literature on both colloidal nanostructures and multilayered compounds, emphasizing that availability of accurate structural information is of dramatic importance to reach a fair understanding of quantum and dielectric confinement effects. Layered halide perovskites occupy a special place in the history of halide perovskites, with a large number of seminal papers in the 1980s and 1990s. In recent years, the rationalization of structure–properties relationship has greatly benefited from new theoretical approaches dedicated to their electronic structures and optoelectronic properties, as well as a growing number of contributions based on modern experimental techniques. This is a necessary step to provide in-depth tools to decipher their extensive chemical engineering possibilities which surpass the ones of their 3D bulk counterparts. Comparisons to classical semiconductor nanostructures and 2D van der Waals heterostructures are also stressed. Since 2015, colloidal nanostructures have undergone a quick development for applications based on light emission. Although intensively studied in the last two years by various spectroscopy techniques, the description of quantum and dielectric confinement effects on their optoelectronic properties is still in its infancy.
关键词： quantum confinement,multilayered perovskites,structural engineering,colloidal nanostructures,hybrid halide perovskites,optoelectronic properties,2D materials,dielectric confinement
更新于2025-09-23 15:23:52
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Two-dimensional Hybrid Halide Perovskites: Principles and Prom-ises
摘要： Hybrid halide perovskites have become the “next big thing” in emerging semiconductor materials as the past decade witnessed their successful application in high-performance photovoltaics. This resurgence has seen enormous and widespread development of the three-dimensional (3D) perovskites, spearheaded by CH3NH3PbI3. The next generation of halide perovskites, however, is characterized by reduced dimensionality perovskites, emphasizing on the two-dimensional (2D) perovskite derivatives which expand as a more diverse subgroup of semiconducting hybrids that possesses even higher tunability and excellent photophysical properties. In this perspective, we begin with a historical flashback that traces back to early reports before the “perovskite fever” and we follow this original work to its fruition in the present day, where 2D halide perovskites are on the spotlight of current research, thriving on several aspects of high-performance optoelectronics. We approach the evolution of 2D halide perovskites from a structural perspective, providing a classification for the diverse structure-types of the materials, which largely dictate the unusual physical properties observed. We sort out the 2D hybrid halide perovskite based on two key components: the inorganic layers and their modification and the organic cation diversity. As these two heterogeneous components blend, either by synthetic manipulation (shuffling the organic cations or inorganic elements) or by external stimuli (temperature and pressure), the modular perovskite structure evolves to construct crystallographically defined quantum wells (QW). The complex electronic structure that arises is sensitive to the structural features that could be in turn used as a knob to control the dielectric and optical properties the QWs. We conclude this perspective with the most notable optoelectronic device achievements that have been demonstrated to date with an eye towards future material discovery and potential technological developments.
关键词： two-dimensional (2D) perovskite derivatives,optoelectronic devices,quantum wells (QW),Hybrid halide perovskites,semiconducting hybrids
更新于2025-09-23 15:21:01
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DFT study of electronic structure and optical properties of layered two-dimensional CH <sub/>3</sub> NH <sub/>3</sub> PbX <sub/>3</sub> (X=Cl, Br, I)
摘要： Two-dimensional (2D) organic–inorganic hybrid halide perovskites (OIHPs) have been considered by researchers in the field of solar cells due to their high-temperature stability. In this paper, the electronic and optical properties of single-layer (SL) and multilayer (ML) structures of MAPbX3 (X = Cl, Br, I and MA = CH3NH3) have been studied by density functional theory (DFT) in order to predict its photovoltaic capabilities. The results have shown that SL- and ML-MAPbX3 have a direct band gap in the range of 1.76–2.70 eV. The calculation of dielectric constants has depicted that the static dielectric constants (SDCs) of SL-MAPbX3 are smaller than SDCs of ML-MAPbX3. However, as we expected, the reaction of the structures to in-plane (║) and out-of-plane (┴) polarizations was different; therefore, the SL- and ML-MAPbX3 (X = Cl, Br, I) were optically anisotropic. In addition, the intensity of the optical absorption spectrum for ML-MAPbX3 structures is approximately three times higher than that of SL-MAPbX3 structures. By increasing the radius of halogens (RCl<RBr<RI), surface area under the absorption curve increases and absorbs more. Furthermore, our results have shown that the electronic and optical behavior of 2D-MAPbX3 is suitable for photovoltaic applications and makes them useful for OIHP solar cells.
关键词： optical properties,DFT,2D-MAPbX3,organic–inorganic hybrid halide perovskites,solar cell
更新于2025-09-19 17:15:36