Butanediammonium Salt Additives for Increasing Functional and Operando Stability of Light-Harvesting Materials in Perovskite Solar Cells.

Organic diammonium cations are a promising component of both layered (2D) and conventional (3D) hybrid halide perovskites in terms of increasing the stability of perovskite solar cells (PSCs). We investigated the crystallization ability of phase-pure 2D perovskites based on 1,4-butanediammonium iodide (BDAI2) with the layer thicknesses n = 1, 2, 3 and, for the first time, revealed the presence of a persistent barrier to obtain BDA-based layered compounds with n > 1. Secondly, we introduced BDAI2 salt into 3D lead−iodide perovskites with different cation compositions and discovered a threshold-like nonmonotonic dependence of the perovskite microstructure, optoelectronic properties, and device performance on the amount of diammonium additive.

Nonmonotonic Photostability of BAMAPbI Homologous Layered Perovskites.

Layered lead halide perovskites (2D LHPs) are attracting considerable attention as a promising material for a new generation of solar cell devices. LHPs have been presented as a more stable alternative to the more widespread 3D bulk perovskite materials; however, a critical analysis of their photostability is still lacking. In this work, we perform a comparative study between BAMAPbI (BA─butylammonium and MA─methylammonium) 2D LHPs with different dimensionalities ( = 1-3) and MAPbI 3D perovskites.

Structural Disorder in Layered Hybrid Halide Perovskites: Types of Stacking Faults, Influence on Optical Properties and Their Suppression by Crystallization Engineering.

Layered hybrid halide perovskites (LHHPs) are an emerging type of semiconductor with a set of unique optoelectronic properties. However, the solution processing of high-quality LHHPs films with desired optical properties and phase composition is a challenging task, possibly due to the structural disorder in the LHHP phase. Nevertheless, there is still a lack of experimental evidence and understanding of the nature of the structural disorder in LHHPs and its influence on the optical properties of the material.

New Features of Photochemical Decomposition of Hybrid Lead Halide Perovskites by Laser Irradiation.

We found that laser irradiation, being widely used in perovskite photovoltaics for both laser scribing and materials characterization, inevitably causes a cascade of complex photo- and thermochemical conjugated reactions, material melting, and ablation with deep morphological and composition changes of perovskite thin films over a much larger area compared to the initial laser spot. A crucial issue in the advancing or suppression of these degradation processes is related to the origin of the surrounding atmosphere. In particular, an effective approach utilizing an inert gas flow directed onto the exposed area is suggested for the first time to eliminate the negative consequences of perovskite laser scribing.