See all entries for this property (5 total)
Crystal system: trigonal
| a: | 8.9817 (±0.0013) Å |
| b: | 8.9817 (±0.0013) Å |
| c: | 11.006 (±0.002) Å |
| α: | 90° |
| β: | 90° |
| γ: | 120° |
Starting materials: HC(NH2)2I, PbI2,distilled HI (57% aqueous) (99.95%), H3PO2 (50% aqueous)
Product: Black FAPbI3 Crystals (alpha phase)
Description: Charge 100 ml 2-necked round bottom flask with a mixture of aqueous HI (6.8 ml, 7.58M) and aqueous H3PO2 (1.7 ml, 9.14M). The liquid was degassed by passing a stream of nitrogen through it for 1 min and keeping it under a nitrogen atmosphere throughout the experiment. Dissolve PbI2 (462 mg, 1 mmol) in the mixture upon heating the flask to 120 °C using an oil bath, under constant magnetic stirring, forming a bright yellow solution. Add solid HC(NH2)2I (172 mg, 1 mmol). Evaporate solution to approximately half its original volume by heating at 120 °C. Stop stirring and leave the solution to evaporate at 100 °C. Black hexagonal (8 faces) or trigonal (5 faces) crystals of the title compound were precipitated and grown at this temperature. After standing for 2-3 h at 100 °C, under a nitrogen atmosphere, set the temperature to 80 °C for a further 2-3 h. Repeat the previous step for two more times to reach 60 °C and 40 °C at which point the solution was left to come to room temperature by powering off the hotplate. The crystals were collected by filtration and washed with anhydrous EtOH.
Method: Single crystal X-ray diffraction
Description: Single-crystal X-ray diffraction experiments were performed using either an STOE IPDS II or IPDS 2T diffractometer using Mo Kα radiation (λ = 0.71073 Å) and operating at 50 kV and 40 mA. Integration and numerical absorption corrections were performed using the X-AREA, X-RED, and X-SHAPE programs. Refer to page 9025 Table 1.
Comment: This compound was assigned the trigonal space group P3m1 in the original publication (doi: 10.1021/ic401215x) and this assignment is therefore retained here. However, the literature consensus for the alpha phase of formamidinium, including a later report by some of the same authors (https://doi.org/10.1002/anie.201609538), is that the compound crystallizes in the cubic space group Pm-3m. Those later reports are considered more accurate.
See all entries for this property (3 total)
Crystal system: hexagonal
| Photoluminescence peak position, Å |
|---|
Starting materials: Lead (II) acetate trihydrate (Pb(ac) 2·3H2O, 99%), fomamidine acetate salt (FAac, 99%), lead iodide (PbI2 , 99.999%), hydriodic acid (HI) (57% w/w aq. soln., stabilized with H3PO2), and gamma-butyrolactone (GBL, 99%) were purchased from Sigma-Aldrich
Product: FAPbI3 Single-crystal 5 mm yellow
Description: Synthesis of Seed Crystal of FAPbI3: Dissolve 2.5 g Pb(ac)2 ·3H2O in 15 mL of HI in a 100 mL flask in a 105 °C oil bath. Add 1.5 mL HI solution and 0.7 g of FAac to the mixed acid solution. Decrease the temperature of the mixed solution to 70 °C; maintain temperature for 6 h for the precipitation of seed crystal FAPbI3 (≈1 mm in size). Wash crystals with diethyl ether and dry in vacuum. Synthesis of Single Crystal FAPbI3: Dissolve 1.0 M solution containing PbI2 and FAI (1:1) was in GBL at 60 °C overnight. Filter the solution using PTFE filter with 0.2 µm pore size. Place seed crystals into this GBL solution in oil bath ≈100–105 °C for 3 h to grow larger crystals. Replace with fresh precursor to obtain an even larger crystal. Repeat this process three times to obtain a large single crystal FAPbI3 in alpha phase. The crystals turn to the yellow delta-phase in 10 days. Refer to Page 2257 Experimental section.
Method: Photoluminescence
Description: NKT SuperK Extreme laser with an excitation of 475 nm and New Focus Si fW detector. Refer to SI Figure S5.
Crystal system: unknown
| Band gap (optical, diffuse reflectance), eV |
|---|
Starting materials: HC(NH2)2I, PbI2, distilled HI (57% aqueous) (99.95%), H3PO2 (50% aqueous)
Product: Black FAPbI3 Crystals (α phase)
Description: Charge 100 ml 2-necked round bottom flask with a mixture of aqueous HI (6.8 ml, 7.58M) and aqueous H3PO2 (1.7 ml, 9.14M). The liquid was degassed by passing a stream of nitrogen through it for 1 min and keeping it under a nitrogen atmosphere throughout the experiment. Dissolve PbI2 (462 mg, 1 mmol) in the mixture upon heating the flask to 120 °C using an oil bath, under constant magnetic stirring, forming a bright yellow solution. Add solid HC(NH2)2I (172 mg, 1 mmol). Evaporate solution to approximately half its original volume by heating at 120 °C. Stop stirring and leave solution to evaporate at 100 °C. Black hexagonal (8 faces) or trigonal (5 faces) crystals of the title compound were precipitated and grown at this temperature. After standing for 2-3 h at 100 °C, under a nitrogen atmosphere, set temperature to 80 °C for a further 2-3 h. Repeat the previous step for two more times to reach 60 °C and 40 °C at which point the solution was left to come to room temperature by powering off the hotplate. The crystals were collected by filtration and washed with anhydrous EtOH.
Method: Optical-diffuse reflectance
Description: Optical diffuse-reflectance measurements were performed at room temperature using a Shimadzu UV-3101 PC double-beam, double-monochromator spectrophotometer operating from 200 to 2500 nm. BaSO4 was used as a nonabsorbing reflectance reference. The generated reflectance-versus-wavelength data were used to estimate the band gap of the material by converting reflectance to absorbance data according to the Kubelka−Munk equation: α/S =(1 − R)^2/2R, where R is the reflectance and α and S are the absorption and scattering coefficients, respectively. Refer to Page 9029 Figure 9.
Comment: Black FAPbI3 Crystals (α phase)
Starting materials: CH3NH3PbBr3
Product: CH3NH3PbI3
Description: The hybrid perovskite (CH3NH3PbBr3) was converted at low temperature via anion exchange to produce a CH3NH3PbI3.
Method: I-V Test Device
Description: The I-V characteristics of CH3NH3PbI3 were determined by using a Keithley 2636 source-measure unit, which was coupled to a 60X objective in an inverted microscope. This was performed by with a set up of a 100 ms pulse as the device was electrically contacted a soft probe (Picoprobe T 4-10) coated with indium gallium eutectic (Aldrich).
Comment: The circuit current density and slope of CH3NH3PbI3 were measured.
See all entries for this property (2 total)
Starting materials: FAI, PbI2, N,N-dimethylformamide (DMF)
Product: FAPbI3 film
Description: FAI and PbI2 were dissolved in anhydrous DMF in a 1:1 molar ratio, at 0.88M. 60µl of hydroiodic acid (57%w/w) was added to 1ml of the solution. The FAPbI3 precursor was diluted down to 0.55M with DMF. The precursor solution was spin-coated and annealed on glass in a nitrogen-filled glovebox at 170°C for 25 minutes.
Method: optical absorption
Description: Transmittance and reflectance spectra were collected with a Varian Cary 300 UV-Vis spectrophotometer with an internally coupled integrating sphere.