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Hybrid organometal halide perovskites (HP) present exceptional optoelectronic properties, but their poor long‐term stability is a major bottleneck for their commercialization. Herein, a solvent‐free approach to growing single‐crystal organic nanowires (ONW) is presented, along with nanoporous metal oxide scaffolds and HP, to form a core@multishell architecture. The synthesis is carried out under mild vacuum conditions employing thermal evaporation for the metal‐free phthalocyanine (H2Pc) nanowires, which are the core, plasma‐enhanced chemical vapor deposition (PECVD) for the TiO2 shell, and co‐evaporation of lead iodide (PbI2) and methylammonium iodide (CH3NH3I/MAI) for the CH3NH3PbI3 (MAPbI3/MAPI) perovskite shell. A detailed characterization of the nanostructures by electron microscopy, (S)‐TEM, and X‐ray diffraction, XRD, is presented, revealing a different crystallization of the HP depending on the template: while the growth on H2Pc nanowires induces the typical MAPI tetragonal structure, a low‐dimensional phase (LDP) is observed on the 1D‐TiO2 nanotubes. Such a combination yields an unprecedentedly stable photoluminescence emission over 20 h and over 300 h after encapsulation in polymethyl methacrylate (PMMA) under different atmospheres including N2, air, and high moisture levels. Moreover, the unique 1D morphology of the system, together with the high refractive index, allows for a strong waveguiding effect along the HP nanowire length. [ABSTRACT FROM AUTHOR]

Despite the youthfulness of hybrid halide perovskite solar cells, their efficiencies are currently comparable to commercial silicon and have surpassed quantum‐dots solar cells. Yet, the scalability of these devices is a challenge due to their low reproducibility and stability under environmental conditions. However, the techniques reported to date to tackle such issues recurrently involve the use of solvent methods that would further complicate their transfer to industry. Herein a reliable alternative relaying in the implementation of an ultrathin plasma polymer as a passivation interface between the electron transport layer and the hybrid perovskite layer is presented. Such a nanoengineered interface provides solar devices with increased long‐term stability under ambient conditions. Thus, without involving any additional encapsulation step, the cells retain more than 80% of their efficiency after being exposed to the ambient atmosphere for more than 1000 h. Moreover, this plasma polymer passivation strategy significantly improves the coverage of the mesoporous scaffold by the perovskite layer, providing the solar cells with enhanced performance, with a champion efficiency of 19.2%, a remarkable value for Li‐free standard mesoporous n‐i‐p architectures, as well as significantly improved reproducibility. [ABSTRACT FROM AUTHOR]

The opto-electronic properties of small-molecules and functional dyes usually differ when incorporated into solid matrices with respect to their isolated form due to an aggregation phenomenon that alters their optical and fluorescent properties. These spectroscopic modifications are studied in the framework of the exciton theory of aggregates, which has been extensively applied in the literature for the study of molecular aggregates of the same type of molecules (homoaggregation). Despite the demonstrated potential of the control of the heteroaggregation process (aggregation of different types of molecules), most of the reported works are devoted to intramolecular aggregates, complex molecules formed by several chromophores attached by organic linkers. The intramolecular aggregates are specifically designed to hold a certain molecular structure that, on the basis of the exciton theory, modifies their optical and fluorescent properties with respect to the isolated chromophores that form the molecule. The present article describes in detail the incorporation of Rhodamine 6G (Rh6G) and 800 (Rh800) into polymeric matrices of poly-(methyl methacrylate), PMMA. The simultaneous incorporation of both dyes results in an enhanced fluorescent emission in the near-infrared (NIR), originating from the formation of ground-state Rh6G–Rh800 intermolecular heteroaggregates. The systematic control of the concentration of both rhodamines provides a model system for the elucidation of the heteroaggregate formation. The efficient energy transfer between Rh6G and Rh800 molecules can be used as wavelength shifters to convert effectively the light from visible to NIR, a very convenient wavelength range for many practical applications which make use of inexpensive commercial detectors and systems. [ABSTRACT FROM AUTHOR]

In this paper the fabrication of highly porous 1D nanostructures by a vacuum and plasma etching combined protocol is presented. Zn-phthalocyanine (ZnPc) is utilized as a solid precursor to form the ZnO. First the ZnPc is sublimated in low argon pressure. Depending on the substrate temperature and microstructure, polycrystalline films or single crystal ZnPc nanowires are grown. These starting materials are then subjected to a remote plasma oxidizing treatment. Experimental parameters such as substrate position, plasma power, treatment duration, and substrate temperature determine the microstructure and properties of the final ZnO nanostructures. The article gathers an in depth study of the obtained porous nanostructured films following scanning and transmission electron microscopy (SEM and TEM), X-ray photoelectron spectroscopy (XPS), X-ray Diffraction (XRD), UV-Vis transmittance, and fluorescence spectroscopies. [ABSTRACT FROM AUTHOR]

Perovskite Solar Cells: Enhanced Stability of Perovskite Solar Cells Incorporating Dopant-Free Crystalline Spiro-OMeTAD Layers by Vacuum Sublimation (Adv. Keywords: organometal halide perovskites; perovskite solar cells; solid state hole conductors; Spiro-OMeTAD; stability; vacuum deposition Organometal halide perovskites, perovskite solar cells, solid state hole conductors, Spiro-OMeTAD, stability, vacuum deposition. [Extracted from the article]

The main handicap still hindering the eventual exploitation of organometal halide perovskite‐based solar cells is their poor stability under prolonged illumination, ambient conditions, and increased temperatures. This article shows for the first time the vacuum processing of the most widely used solid‐state hole conductor (SSHC), i.e., the Spiro‐OMeTAD [2,2′,7,7′‐tetrakis (N,N‐di‐p‐methoxyphenyl‐amine) 9,9′‐spirobifluorene], and how its dopant‐free crystalline formation unprecedently improves perovskite solar cell (PSC) stability under continuous illumination by about two orders of magnitude with respect to the solution‐processed reference and after annealing in air up to 200 °C. It is demonstrated that the control over the temperature of the samples during the vacuum deposition enhances the crystallinity of the SSHC, obtaining a preferential orientation along the π–π stacking direction. These results may represent a milestone toward the full vacuum processing of hybrid organic halide PSCs as well as light‐emitting diodes, with promising impacts on the development of durable devices. The microstructure, purity, and crystallinity of the vacuum sublimated Spiro‐OMeTAD layers are fully elucidated by applying an unparalleled set of complementary characterization techniques, including scanning electron microscopy, X‐ray diffraction, grazing‐incidence small‐angle X‐ray scattering and grazing‐incidence wide‐angle X‐ray scattering, X‐ray photoelectron spectroscopy, and Rutherford backscattering spectroscopy. [ABSTRACT FROM AUTHOR]

Front Cover: Nowadays, highly porous ZnO materials play a key role as nanosensors, solar cells, photonics devices and photo‐catalysts. The protocol developed in this work combines physical vapour deposition and remote plasma etching using Zn‐phthalocyanine as vacuum processable precursor for foam‐like layers and 1D nanostructures. The methodology for the fabrication of ZnO nanostructures is straightforwardly extensible to an ample range of porous metal oxides just selecting the metal‐phthalocyanine/porphyrin sublimable precursors. Further details can be found in the article by Maria Alcaire et al. on page 287. [ABSTRACT FROM AUTHOR]