Many multication perovskites for highly stable and efficient solar cells benefit from rubidium iodide introduced in the precursor solution. It is well known that Rb + influences positively the optoelectronic and mobility properties and has a direct effect upon crystallization and halide homogenization. As Rb + is often incorporated by adding RbI in the precursor solution, it can be difficult to distinguish the influence of Rb + and Iseparately.Herein, we report a post-passivation of methylammonium-free (CsFA) perovskite films with rubidium butyrate (RbBu). The passivation with RbBu increases the hydrophobicity of the perovskite surface and passivates shallow and deep traps, leading to an increase of chargecarrier lifetimes and diffusion lengths. Consequently, a better photovoltaic performance is also observed. These superior properties are attributed to both surface (halide-vacancy) and grain-boundary passivation by the carboxylate group and Rb + , respectively. We found that Rb + itself acts as a direct and powerful passivating agent for multication perovskites, and this is proven by decoupling its contribuition and halide's contribuition to other important performance parameters (e.g. crystallization, halide vacancies filling, etc).

We report the connection between the piezoelectric effect and the crystalline structure of NaNbO3. Rietveld refinement and piezoresponse force microscopy were important tools to discover that the fibers are composed of a mix of phases.

This work reports the transformation of a layered aluminophosphate (AlPO-CJ70) with N,N-dimethylbenzylamine as SDA and inorganic layers containing two different Al sites and three P sites, where two of them are ≡P=O sites and the other is a =P(OH)=O group, in three dimensional silicoaluminophosphates with structures analogous to SAPO-5 and SAPO-15. The synthetic process of the 3D materials are different. The SAPO-5 analogue, called UEC-4, was synthesized in an aqueous media in the presence of TEABr and silica, and the SAPO-15 analogue, UEC-5, was synthetised by a dry-gel conversion method in the presence of n-butylamine and silica. Both materials were characterized with powder X-rays diffraction, solid state nuclear magnetic ressonance, infrared spectroscopy, scanning electron microscopy and termogravimetry.

This work reports the characterization using solid-state NMR of the second generation of the UEC family of molecular sieves, such generation is composed by two tridimensional silicoaluminophosphates synthesized from a layered aluminophosphate (AlPO-CJ70). The 3D structures are analogous to SAPO-5 (UEC-4) and SAPO-15 (UEC-5), both were characterized using multinuclear solid-state NMR, 27Al-MQ-MAS and 29Si{27Al} TRAPDOR.

Zeolitic structures can be synthetized in many ways, one of them is to use a layered precursor as source of T atoms (Si, Al, P, …) in the presence or absence of organic structure directing agent (SDA). In this work the possibility of using a layered aluminophosphate, with N,N-dimethylbenzylamine as SDA, in combination with another organic directing agent to create three new zeotypic structures UEC-4, -5 and -6 was studied.