Starting materials: Methanol, hexafluorobenzene, (PEA)2SnI4
Product: Thin film on quartz substrate
Description: Films of the intercalated layered perovskites were prepared by immersing the uninteracalated films in a benzene or hexafluorobenzene solution at room temperature for an hour. The films were encapsulated by thin polycarbonate sheet while still wet from their immersion. The encapsulation effectively laminates the hybrid film and provided a partial diffusion barrier for the intercalated species. XRD and optical measurements can be made through the polycarbonate sheet cover.
Method: UV-vis Absorption
Description: Absorption spectra were measured with a Hewlett-Packard UV-vis 8543 spectrophotometer at room temperature on the quartz thin-film samples.
Starting materials: Tin(II) oxide (Sigma Aldrich, 97%), hydriodic acid (Sigma Aldrich, 57% w/w in H2O, 99.9%), hypophosphorous acid (Avra, 50% w/w H2O), phenylethylamine (Sigma Aldrich, 99.9%), hexafluorobenzene (HFB, Sigma Aldrich, 99%)
Product: (PEA)2SnI4 : HFB crystals
Description: Single crystals of (PEA)2SNI4 were synthesized by adding tin (II) oxide (0.6 mmol), hydriodic acid ( 5 mL), and hypophosphorous acid (3 mL) into a sealed vial and heated at 90 ˚C under constant stirring. After tin (II) oxide dissolved in the solution and yielded a dark yellow color, phenethylamine (1.2 mmol) was injected into the sealed vial by a syringe. A brown sheet of crystals of (PEA)2SNI4 produced after the solution was cooled to room temperature. The crystals were then obtained via filtration. 50 mg of these crystals was dissolved in a mixture of 2 mL methanol and 2 mL HFB. The obtained dark yellow solution was kept open in a glove box. As the solvent evaporates (PEA)2SnI4:HFB crystals precipitate out. The crystals were filtered, dried and stored in a glove box for further use.
Method: UV-visible absorption
Description: Optical diffuse-reflectance spectra were collected at room temperature using a Shimadzu UV-3600 plus UV-VIS-NIR spectrophotometer. The reflectance spectra were converted to absorbance by using the Kubelka-Munk transformation; (α/S = (1 − R)^2/2R); α is the absorption coefficient, S is the scattering coefficient, and R is the reflectance.