Highly Stable Thin Films Based on Novel Hybrid 1D (PRSH)PbX3 Pseudo-Perovskites

In this study, the structure and morphology, as well as time, ultraviolet radiation, andhumidity stability of thin films based on newly developed 1D (PRSH)PbX3 (X = Br, I) pseudoperovskite materials, containing 1D chains of face-sharing haloplumbate octahedra, areinvestigated. All films are strongly crystalline already at room temperature, and annealing does notpromote further crystallization or film reorganization. The film microstructure is found to bestrongly influenced by the anion type and, to a lesser extent, by the DMF/DMSO solvent volumeratio used during film deposition by spin-coating. Comparison of specular X-ray diffraction andcomplementary grazing incidence X-ray diffraction analysis indicates that the use of DMF/DMSOmixed solvents promotes the strengthening of a dominant 100 or 210 texturing, as compared thecase of pure DMF, and that the haloplumbate chains always lie in a plane parallel to the substrate.Under specific DMF/DMSO solvent volume ratios, the prepared films are found to be highly stablein time (up to seven months under fluxing N2 and in the dark) and to highly moist conditions (upto 25 days at 78% relative humidity). Furthermore, for representative (PRSH)PbX3 films, resistanceagainst ultraviolet exposure (? = 380 nm) is investigated, showing complete stability after irradiationfor up to 15 h at a power density of 600 mW/cm2. These results make such thin films interesting forhighly stable perovskite-based (opto)electronic devices.