Unveiling the additive-assisted oriented growth of perovskite crystallite for high performance light-emitting diodes.

Solution-processed metal halide perovskites have been recognized as one of the most promising semiconductors, with applications in light-emitting diodes (LEDs), solar cells and lasers. Various additives have been widely used in perovskite precursor solutions, aiming to improve the formed perovskite film quality through passivating defects and controlling the crystallinity. The additive's role of defect passivation has been intensively investigated, while a deep understanding of how additives influence the crystallization process of perovskites is lacking. Here, we reveal a general additive-assisted crystal formation pathway for FAPbI3 perovskite with vertical orientation, by tracking the chemical interaction in the precursor solution and crystallographic evolution during the film formation process. The resulting understanding motivates us to use a new additive with multi-functional groups, 2-(2-(2-Aminoethoxy)ethoxy)acetic acid, which can facilitate the orientated growth of perovskite and passivate defects, leading to perovskite layer with high crystallinity and low defect density and thereby record-high performance NIR perovskite LEDs (~800 nm emission peak, a peak external quantum efficiency of 22.2% with enhanced stability)

Development of a Novel Terpolymer as a Green and Efficient Decalcifying Agent for Crude Petroleum

A novel environmental decalcifying agent was prepared with allylpolyethoxy amino carboxylate (APEAA), hydroxyethyl acrylate (HEA), and maleic anhydride (MA) by means of free-radical polymerization in an aqueous solution. The morphology and structure of the samples were characterized through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, and ¹H nuclear magnetic resonance (¹H NMR) spectra. The molecular-weight distribution of APEAA–HEA–MA was determined by the gel permeation chromatography method. APEAA–HEA–MA was used as a green decalcifying agent to remove calcium from crude petroleum, and the impact of factors such as monomer ratio, copolymerization time, dosages, and desalination temperature was analyzed. It is found that the decalcification rate of APEAA–HEA–MA could reach to its maximum, and the calcium removal efficiency was approximately 97.88% when the monomer molar ratio of APEAA–HEA–MA was 1:2:5, the reaction time of copolymerization was 2 h, the dosage was 100 ppm, and the desalination temperature was 100 °C. This research work can promote the exploration on facile synthesis of a novel terpolymer and its potential application in refinery desalting processes