See all entries for this property (35 total)
Crystal system: cubic
| a: | 12.4984 (±0.0007) Å |
| b: | 12.5181 (±0.0007) Å |
| c: | 12.6012 (±0.0008) Å |
| α: | 90° |
| β: | 90° |
| γ: | 90° |
Method: Single-Crystal X-ray Diffraction
Description: Frames were collected using a Bruker D85 diffractometer equipped with a Photon 100 CMOS detector. Synchrotron X-rays at Beamline 11.3.1 at the ALS, LBNL were monochromated using silicon(111).
Starting materials: PbCO3 (2.67 g, 0.01 mol), CH3(CH2)3NH3I (1.34 g, 0.0067 mol), CH3CH2NH3I (1.15 g, 0.0067 mol)
Product: FEP, AFEP, PEP
Description: Lead iodide hybrid perovskites, (BA)2,(EA)2Pb3I10, were synthesized in a concentrated HI solution (40 mL, 57%) that contained PbCO3, CH3(CH2)3NH3I, CH3CH2NH3I.
Method: Temperature-cooling, Powder X-RAY Diffraction and Differential Scanning Calorimetry (DSC)
Description: Crystals of the hydroiodic solutions were obtained via a temperature- cooling method using differential scanning calorimetry (DSC) measurements with a heating/cooling rate of 10 K/min. The DSC traced reversible thermal peaks at 322/315 K (T1) and 363/360 K (T2) in the heating/cooling mode. The preparation of the HI solutions performed at 50°C and kept at 4-6 °C above its preliminary saturated temperature. The temperature was then slowly lowered with a cooling rate of 0.5 K/day, which resulted in bulk dark-red crystals. In addition, a bright yellow solution was obtained from heating the synthesis of compound 1 in an HI solution. These crystals were then verified via powder X-ray diffraction at room temperature. The temperature dependence of the dielectric constant was measured using the double-wave method to
See all entries for this property (3 total)
Starting materials: PbI2, MAI
Product: thin film
Description: The film is produced using a dynamic two-step deposition method. on a compact TiO2/ATO substrate, a N,N-dimethylformamide (DMF) solution of PbI2 is spin coated at 3000 rpm for 10 s, and an isopropyl alcohol solution of methylammonium iodide (MAI) is immediately added dropwise, while keeping the whole spinning time 20 s prior to the end of spin coating. The yellow PbI2 solution turns to brown immediately and gradually darkens during the spin coating. After annealing at 150 °C for 10 min, the as-prepared perovskite film has a shiny black color due to the high visible light absorption and super flat surface. The cross-linking agent 2-aminoterephthalic acid (with different concentrations of 0, 0.2, 0.5, and 1 mg mL−1) was immediately spin-coated on the MAPbI3 film and subsequently annealed at 150 °C for 5 min.
Method: UV-Vis absorption
Description: The absorption spectra were collected by a UV-visible spectrophotometer (UV-3600, Shimadzu Corp.)
See all entries for this property (5 total)
Crystal system: orthorhombic
| Temperature, K | Photoluminescence peak position, eV |
|---|
Starting materials: Methylamine (40% in methanol), hydroiodic acid (57 wt% in water), PbI2, g-butyrolactone, H2O2, NH4OH, Si wafer
Product: MAPbI3 film
Description: React 30 mL of methylamine and 32.3 mL of hydroiodic acid at 0 °C for 2 h. Evaporate solvents at 50 °C. Wash the yellowish raw CH3NH3I with diethyl ether by stirring the solution for 30min for a total of three times. Recrystallize CH3NH3I from a mixed solvent of diethyl ether and ethanol. Collect the solid and dry at 60 °C in a vacuum oven for 24 h. Treat Si wafer with an aqueous solution of H2O2 and NH4OH with a volume ratio of H2O2 : NH4OH : H2O = 1 : 1 : 5 for 30 min. Drop a 40 wt% precursor solution of equimolar CH3NH3I and PbI2 in g-butyrolactone onto the Si wafer to form the MAPbI3 film. Spin-coat at 1500 rpm for 30 s, and then at 2500 rpm for 40 min in air. Upon drying at room temperature, color change indicates the formation of MAPbI3 in the solid state. Anneal the MAPbI3 film in air for 15 min at 100 °C.
Method: Photoluminescence
Description: Steady-state and time-resolved PL spectra were measured using an Edinburgh FLS920 spectroscopy system using laser excitation at 405 nm. PL peak is due to near-band edge transition. [Results and discussion paragraph 3; Fig. 2(b) Peak_OI]
Comment: Grain size were 100-500 nm diameter
See all entries for this property (6 total)
Crystal system: tetragonal
| Band gap (optical, diffuse reflectance), eV |
|---|
Starting materials: Lead(II) acetate (Chemical Reagents, Sigma), concentrated aqueous HI, CH3NH2 (40% soluble in water, Merck)
Product: MAPbI3 Single crystal
Description: Precipitate polycrystalline MAPbI3 from a halogenated acid solution using the method of [1]. Dissolve 1.88 g of lead(II) acetate in 40 ml concentrated to 57 wt% HI aqueous solution warmed (~90 °C) in a water bath. Then add another 2 ml of HI solution with 0.45 g CH3NH2. Crystallize by cooling the solution from 90 °C to room temperature over 3 hours. Wash product with acetone and dry overnight at 100 °C in a vacuum oven. Obtain larger crystals via slow cooling from 90 to 50 °C over 3 days. Refer to Page 9299 Section 2.1 Synthesis.
Comment: Black crystals; Synthesis references: [1] A. Poglitsch and D. Weber, J. Chem. Phys., 1987, 87, 6373–6378. [2] Q. Xu, T. Eguchi, H. Nakayama, N. Nakamura and M. Kishita, Z. Naturforsch., A: Phys. Sci., 1991, 46, 240–246.
Method: UV-Vis absorption (diffuse reflectance)
Description: UV-Visible-NIR spectrophotometer (Shimadzu UV-3600) with integrating sphere attachment (ISR-3100) operating in the 300–1500 nm region. Highly refined barium sulfate powder (Wako, pure) was used as a reflectance standard. Optical absorption coefficient was determined according to the Kubelka–Munk equation. In this manner, optical band gaps for the perovskites were determined. Refer to Page 9300 Section 3.1 Paragraph 3; Figure 3,4.
See all entries for this property (20 total)
| Initial crystal system | unknown |
| Final crystal system | unknown |
| Initial space group | unknown |
| Final space group | unknown |
| Direction | both |
| Phase transition temperature | 168.0 K |
Hysteresis: NIL
| Initial crystal system | unknown |
| Phase transition temperature | K |
Starting materials: HI, CH3NH2, Pb(NO3)2
Product: Partially deuterated MAPbI3
Description: Add concentrated HI to neutralize 20 g of 40% CH3NH2 aqueous solution. Add 7.1 g (0.021 mol) of Pb(NO3)2 solution drop-wise under vigorous stirring at 100°C to the concentrated CH3NH2I solution. Organic crystals form while dripping in the solution. Cool the solution to not below 40°C and filter out the crystals. Wash crystals firstly with n-butanol and then with benzene; subsequently dry crystals in vacuum. Partially N-deuterated samples required for the NMR studies were prepared using D-containing solutions. Refer to Page 413 Experimental.
Comment: Synthesis references: [1] Canadian Journal of Chemistry, 1987, 65(5): 1042-1046 https://doi.org/10.1139/v87-176 [2] D. WEBER. Z. Naturforsch. 33b, 1443 (1978).
Method: 2H and 14N NMR
Description: Measurements were carried out at 8.48 T with a Nicolet 360NB spectrometer using a broad band (16-58 MHz) variable-temperature 10 mm probe supplied by Nicolet. The 2-H and 14-N frequencies were 55.427 and 26.083 MHz, respectively. Refer to Page 414 Results section Existence of transitions subsection.