We demonstrate the formation of a well-organized thin film of two-dimensional (2D) layered (CHNH)PbI hybrid perovskite by immersing octadecyl amine (ODA) Langmuir-Blodgett (LB) films in an aqueous solution of PbI/HI. The immersed films exhibit a sharp absorption band at 486 nm (2.55 eV), which is assigned to the excitonic absorption.
View Article and Find Full Text PDFThe enigmatic self-assembling ability of nanodiamond (ND) particles has been discovered herein. Diamond-rich crystalline nanosheets with thickness of approximately ∼25 nm were grown from a Langmuir monolayer of arachidic acid (AA) at the interface between air and a dilute aqueous ND solution. Their fine rectangular shapes with uniform uniaxial birefringence indicate appreciable crystallinity, thus supporting that they are hydrated colloidal crystals of homogeneous ND particles.
View Article and Find Full Text PDFSpherulitic crystallization in Langmuir-Blodgett (LB) films of the ditetradecyldimethylammonium-Au(dmit) [2CNMe-Au(dmit)] salt has been characterized by polarized light microscopy, Fourier-transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) analyses. Analyses by differential scanning calorimetry (DSC) for the bulk crystals indicate that annealing in the temperature range of 58-100 °C may be appropriate to improve the order in the LB film. The polarized light microscopy measurement further revealed that a spherulite structure was formed after the film was annealed at 80 °C for 60 min.
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