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Despite the current advancements, yet improving the intrinsic structure and external environmental stability of hybrid metal halide perovskite nanomaterials is required for developing efficient perovskite‐based devices. Up‐to‐date, a very attractive method is growing and/or embedding perovskite nanocrystals within organic polymeric matrices, or into porous inorganic and hybrid nano/micromaterials (e. g. metal‐organic frameworks, mesoporous silica, zeolites, and others), favored through confinement effect within the pores. In this review, we highlighted the last two years of research progress on enhancing the stabilization of perovskite nanoparticles based on methylammonium cations. In the future generation of optoelectronic and photovoltaic devices along with other interesting applied fields, it is predicted that an effective way to trigger the widespread use of this type of perovskite nanocrystals may involve combining different functional host materials, acting as a smarter protection method for the guest nanocrystals. [ABSTRACT FROM AUTHOR]

This work reports on an optimized procedure to synthesize methylammonium bromide perovskite nanoparticles. The ligand-assisted precipitation synthetic pathway for preparing nanoparticles is a cost-effective and promising method due to its ease of scalability, affordable equipment requirements and convenient operational temperatures. Nevertheless, there are several parameters that influence the resulting optical properties of the final nanomaterials. Here, the influence of the choice of solvent system, capping agents, temperature during precipitation and ratios of precursor chemicals is described, among other factors. Moreover, the colloidal stability and stability of the precursor solution is studied. All of the above-mentioned parameters were observed to strongly affect the resulting optical properties of the colloidal solutions. Various solvents, dispersion media, and selection of capping agents affected the formation of the perovskite structure, and thus qualitative and quantitative optimization of the synthetic procedure conditions resulted in nanoparticles of different dimensions and optical properties. The emission maxima of the nanoparticles were in the 508–519 nm range due to quantum confinement, as confirmed by transmission electron microscopy. This detailed study allows the selection of the best optimal conditions when using the ligand-assisted precipitation method as a powerful tool to fine-tune nanostructured perovskite features targeted for specific applications. [ABSTRACT FROM AUTHOR]

Herein, the impact of thin layer of polyphosphazene derivatives, as a buffer layer between the electron‐transporting layer and the back metal‐contact in mixed‐cation mixed‐halide perovskite solar cells (PSCs), is explored. PSCs with a poly[bis(allylamino)phosphazene] (PPz) interlayer exhibit enhanced rectification in the photo‐induced current density–voltage (J–V) curves, which show improved photovoltaic performance and photostability with reduced hysteresis. The thickness of the interlayer is optimized and the optimized PSCs with PPz buffer layer shows an average open‐circuit voltage (VOC) of ≈1.05 V, a short‐circuit current density (JSC) of around 23.5 mA cm−2, a fill factor of ≈72%, and a power conversion efficiency of about 17.3% for the forward and reverse scans under simulated AM1.5G illumination. Moreover, the application of PPz as an electron‐transporting interlayer in organic solar cells reveals that PPz interfacial layer improves the electron extraction at the cathode. The merit of applying PPz interlayer extends to the possibility of using different metals (such as aluminum, gold, copper, and silver) as the top contact in the prepared PCSs. In general, these experiments reveal a very promising approach to tackle the issue of interfacing, and to improve the performance and stability of PSCs. [ABSTRACT FROM AUTHOR]

Combining the unique properties of peptides as versatile tools for nano- and biotechnology with lead halide perovskite nanoparticles can bring exceptional opportunities for the development of optoelectronics, photonics, and bioelectronics. As a first step towards this challenge sub 10 nm methylammonium lead bromide perovskite colloidal nanoparticles have been synthetizes using commercial cyclic peptide Cyclo(RGDFK), containing 5 amino acids, as a surface stabilizer. Perovskite nanoparticles passivated with Cyclo(RGDFK) possess charge transfer from the perovskite core to the peptide shell, resulting in lower photoluminescence quantum yields, which however opens a path for the application where charge transfer is favorable. [ABSTRACT FROM AUTHOR]