Perovskite-based photodetectors (PDs) are broadly utilized in optical communication, non-destructive testing, and smart wearable devices due to their ability to convert light into electrical signals. However, toxicity and instability hold back their mass production and commercialization. The lead-free Cs2AgBiBr6 double perovskite film, promised to be an alternative, is fabricated by electrophoretic deposition (EPD), which compromises film quality. Herein, we improved the quality of the Cs2AgBiBr6 films and the performance of PDs by adding N-acetylethylenediamine (DEAC) to Cs2AgBiBr6 perovskite precursor for EPD, in which the ligand DEAC provides a pair of lone electrons to Bi3+, forming coordinate covalent bonds. The optimized PDs have high detectivity, up to 4.4×1012 Jones, and high stability in the air. The high-performance, flexible Cs2AgBiBr6 perovskite PDs were fabricated on this basis, it also achieved the detectivity up to 3.2×1012 Jones with excellent bending cycle stability. These results propose a feasible approach to improving the crystallization of double perovskite thin films by introducing ligands during the EPD process. Furthermore, they demonstrate enhanced optoelectronic performance, indicating that this method is also applicable to halide perovskites, offering an effective strategy to improve their film quality.
Cationic polyacrylate latex has attracted extensive attention due to its special properties and potential applications in wood primers, metal coatings, and fabric treatments, etc. However, cationic polyacrylate latex has poor durability and stability, which limits its use in practical applications. In this study, a functional cationic monomer (3-chloro-2-hydroxypropyl) dimethyl [2-[(2-methyl-1-oxoallyl)oxy]ethyl] ammonium chloride (DEAC) was combined with two conventional monomers of methyl methacrylate (MMA) and butyl acrylate (BA) to prepare cationic polyacrylate latex by a semi-continuous emulsion polymerization. The obtained latexes showed typical cationic character with zeta potential in the range of + 40 to + 65 mV. The effect of DEAC on the stability of latex was studied and good alkali resistance could be gained at high DEAC content. Water resistance and mechanical properties of the film before and after crosslinking are studied in detail. The results showed that the water absorption reduced from 60.04% to a minimum of 9.18%, and the tensile strength increased from 3.9 to 8.4 MPa, which was comparable to solvent-based polyacrylate films. This work provides a new strategy for the preparation of waterborne cationic polyacrylate latex with improved water resistance and good mechanical properties, etc., which can be applied in papermaking, textiles, wood primers, and other potential fields. Graphical abstract
危险品化学品经营许可证（带存储）