Ethylammonium Lead Iodide Formation in MAPbI3 Precursor Solutions by DMF Decomposition and Organic Cation Exchange Reaction

Abstract

Extra peaks have constantly been observed in the X-ray diffraction measurement for the CH3NH3PbI3 film. Such mysteries have now been uncovered in this paper, in which powder X-ray diffraction, in situ X-ray diffraction, and scanning electron microscopy measurements were conducted, and these peaks were attributed to the ethylammonium lead iodide (CH3CH2NH3PbI3/EAPbI3). It was found that the formation of EAPbI3 was triggered by the breakdown of N, N-dimethylformamide (DMF), which was adopted as the solvent in the preparation of the precursor solutions. EAPbI3 was generated by the organic cation exchange reaction in the subsequent annealing process. A simple solution for this problem is proposed in this paper as well, which would hopefully help the community to eradicate this impurity.

Investigation of Opto-Electronic Properties and Stability of Mixed-Cation Mixed-Halide Perovskite Materials with Machine-Learning Implementation

“…For binary MA-FA mixtures, a significant opto-electronic performance and stability was indicated [43]. MA-EA mixtures have been recently proposed for the fabrication of efficient light-emitting devices [44] and PSCs [45,46], while Wang et al shows the detrimental effect of EAPbI 3 on the perovskite thin film morphology [47]. Similarly, MA-GA mixtures are associated with enhanced stability [41,48].…”

Moisture-Stable FAPbI3 Perovskite Achieved by Atomic Structure Negotiation

“…13 As a result, a great deal of effort has since been devoted to trying to eliminate the water intrusion and impede the phase transition, such as strain engineering, 14,15 interface engineering, 16,17 or doping in the A/ B/X sites in the ABX 3 structure of the perovskite. 18−23 Unfortunately, these quick attempts did not extend the perovskite lifetime to any appreciable level, due not least to the debatable phase transition mechanism, 24,25 in particular, the influence of water molecules on the perovskite structure, in addition to the possible structural variations vis-a-vis the kinetics and thermodynamics. Therefore, such effects were destined to be less than successful.…”

“…Unfortunately, these quick attempts did not extend the perovskite lifetime to any appreciable level, due not least to the debatable phase transition mechanism, , in particular, the influence of water molecules on the perovskite structure, in addition to the possible structural variations vis-a-vis the kinetics and thermodynamics. Therefore, such effects were destined to be less than successful.…”

Computational Simulation of a Three-Dimensional Mg-based Metal–Organic Framework as Nanoporous Anticancer Drug Carrier

“…In the pentanuclear secondary building units (SBUs) of MUT-8 , the Mg3 center lies on an inversion center and adopts an octahedral coordination geometry defined by four carboxylate-oxygen atoms from four different DBrTPA ligands in the equatorial plane and two μ 2 -oxo bridging oxygen atoms from two different formate ligands in axial positions (Figure a). The formate ion is the result of the hydrolysis of DMF in solvothermal conditions. − The Mg2 centers are in a six-coordinate octahedral environment being bonded to four oxygen atoms from four carboxylate groups of four DBrTPA ligands in the equatorial positions and a μ 2 -oxo bridging formate oxygen atom and the oxygen of a terminal DMF in the axial positions. The Mg1 centers also adopt distorted octahedral coordination geometry, indicated by three oxygen atoms from one chelating and one unidentate DBrTPA ligand, an oxygen atom from a μ coordination bridging bidentate formate ion and an oxygen atom from a terminal DMF molecule (Figure a).…”