Starting materials: phenyl ethyl ammonium iodide (C6H5CH2CH2NH3I) and tin iodide (SnI2)
Product: brown-golden plate-like (C6H5CH2CH2NH3)2SnI4 crystals
Description: In an argon atmosphere, 540 mg (2.16 mmol) of C6H5CH2CH2NH3I was mixed with 373 mg (1 mmol) of SnI2 in 10 ml of acetonitrile under stirring. 4 ml of the solvent was evaporated by heating at 75 degrees C. The solution was then cooled to 10 degrees C. Finally, the precipitate was filtered and dried at 40 degrees celsius.
Method: UV-vis absorption
Description: The spectrum was recorded on Varian model 2390 spectrophotometer
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%)
Product: (PEA)2SnI4 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 and were stored in an N2 glove box.
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.
Starting materials: HI, SnI2, phenylethylammonium iodide (PEAI), toluene
Product: Thin film on quartz substrate
Description: Crystals were grown by slowly cooling a solution of HI and PEAI and SnI2. SnI2 was added first, then the organic salt, and then HI. The solution was mixed and heated to 94 degrees Celsius to completely dissolve SnI2. The solution was then cooled at 3 degrees per hour until 0 degrees was reached, resulting in the formation of red crystals. The crystals were filtered in an inert atmosphere and also rectrystallized twice from a solution of methanol and toluene. To produce films of the unintercalated systems, the recrystallized perovskites were dissolved in distilled methanol. Previously cleaned and prepared quartz substrates were used and the solution was spin coated onto them. The spinning cycle was 1 s ramp up to 1800 rpm, and then 30 s at 1800 rpm. Then the samples were annealed at 70 degrees Celsius for 15 minutes to remove any residual solvent.
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.