See all entries for this property (3 total)
Crystal system: orthorhombic
| a: | 8.244 (±0.0006) Å |
| b: | 11.7351 (±0.0011) Å |
| c: | 8.1982 (±0.0008) Å |
| α: | 90° |
| β: | 90° |
| γ: | 90° |
Starting materials: Pb(NO3)2, KBr, HBr (48% aqueous), CsBr, ethanol (EtOH)
Product: orange, transparent crystals
Description: PbBr2 was first synthesized by dissolving Pb(NO3)2 (0.15 mol, 49.6 g) in 100 mL of boiling H2O. Meanwhile, KBr (0.3 mol, 35.7 g) was dissolved in 50 mL of H2O in a separate beaker and then slowly added to the Pb(NO3)2 solution with constant stirring. As a result, PbBr2 immediately precipitated and after 15 minutes of stirring, the solution was cooled to room temperature. The PbBr2 was filtered under vacuum, washed with distilled water, and dried overnight. This product was used in the synthesis of CsPbBr3. The PbBr2 (20 mmol, 7.31 g) was dissolved in 30 mL of HBr (48% wt.). A pale, yellow solution resulted, and CsBr (20 mmol, 4.26 mg) was dissolved in 10 mL of H2O. A bright orange solid immediately precipitated. The solid was suction filtered, washed with EtOH, dried under vacuum. Finally, the Bridgeman Method was performed to obtain single crystals. 6g of CsPbBr3 were ground with mortar and pestle, placed in a silica tub (OD/ID: 9mm/7mm), and the tube compilation was brought to a 10^{-4} mbar vacuum and flame-sealed. Then, the ampoule was attached to a clock mechanism, lowered into a 3-zone vertical tube furnace (temperature gradient: 10º C/mm). Dropping speed varied from 3 to 30 mm/h.
Method: Single Crystal X-ray diffraction
Description: STOE IPDS II or IPDS 2T diffractometer were used. Mo Kα radiation (λ= 0.71073 Å) was performed, and diffractometers were operating at 50 kV and 40 mA. Absorption corrections were executed with X-AREA, X-RED, and X-SHAPE programs. Structures were solved directly and refined by full matrix least squares on F2 with the SHELXTL program package. Rotax functions of PLATON software (in WINGX platform) were used to find correct space group.
Crystal system: orthorhombic
| Band gap (optical, transmission), eV |
|---|
Starting materials: PbBr2 (synthesized), HBr (48% aqueous), CsBr, ethanol (EtOH),
Product: Orange transparent crystals
Description: PbBr2 (7.31 g, 20 mmol) was dissolved in 30 mL HBr solution, and CsBr (4.26 mg, 20 mmol) was dissolved in 10 ml of H2O. Both of these solutions were mixed at room temperature. The obtained orange powder (CsPbBr3) was filtered, washed with EtOH, and dried under a vacuum. 6 g of CsPbBr3 powder was finely ground and loaded in a silica tube. Following this Bridgman method was applied to grow the crystals in a 3-zone vertical tube furnace.
Comment: Details of the crystal growth can be found in the SI of the article.
Method: UV-vis absorbance
Description: The spectrum was recorded using a Shimadzu UV-3101 PC double-beam, double monochromator spectrophotometer. Tauc plot with direct band gap assumption was used to obtain the band gap.
Crystal system: orthorhombic
| Photoluminescence peak position, eV |
|---|
Starting materials: PbBr2 (synthesized), HBr (48% aqueous), CsBr, ethanol (EtOH)
Product: Orange transparent crystals
Description: PbBr2 (7.31 g, 20 mmol) was dissolved in 30 mL HBr solution, and CsBr (4.26 mg, 20 mmol) was dissolved in 10 ml of H2O. Both of these solutions were mixed at room temperature. The obtained orange powder (CsPbBr3) was filtered, washed with EtOH, and dried under a vacuum. 6 g of CsPbBr3 powder was finely ground and loaded in a silica tube. Following this Bridgman method was applied to grow the crystals in a 3-zone vertical tube furnace.
Comment: Details of the crystal growth can be found in the SI of the article.
Method: Photoluminescence
Description: Low temperature PL measurements were performed on polished, etched samples. Excitation source was He-Cd (325 nm) or N2 (337nm) laser. Spectrum was analyzed with 0.75-m SPEX grating monochromator. Signal was detected with R928 Hamamatsu photomultiplier tube (PMT) and phase sensitive detection lock-in system.
Starting materials: PbBr2 (synthesized), HBr (48% aqueous), CsBr, ethanol (EtOH)
Product: Orange transparent crystals
Description: PbBr2 (7.31 g, 20 mmol) was dissolved in 30 mL HBr solution, and CsBr (4.26 mg, 20 mmol) was dissolved in 10 ml of H2O. Both of these solutions were mixed at room temperature. The obtained orange powder (CsPbBr3) was filtered, washed with EtOH, and dried under a vacuum. 6 g of CsPbBr3 powder was finely ground and loaded in a silica tube. Following this Bridgman method was applied to grow the crystals in a 3-zone vertical tube furnace.
Comment: Details of the crystal growth can be found in the SI of the article.
Method: Raman spectroscopy
Description: DeltaNu Advantage NIR spectrometer was used with 785 nm irradiation and a CCD camera detector with backscattered setup. Max power of 60 mW and beam diameter of 35 μm were used. Spectra was collected with integration times of 0.1-1 s.
See all entries for this property (3 total)
Method: UV-vis absorbance
Description: Optical diffuse-reflectance measurements were executed at 298 K with a Shimadzu UV-3101 PC double-beam, double monochromator spectrophotometer between 200 to 2500 nm. One Nicolet 6700 IR spectrometer with a diffuse-reflectance kit was used for 4000-400cm^{-1} region. The reflectance vs. wavelength data was used to convert the data to absorption data via the Kubelka-Munk equation: α/S = (1-R)^2/2R.
See all entries for this property (6 total)
Starting materials: CsBr, PbBr2, dimethyl sulfoxide (DMSO
Product: CsPbBr3 thin film
Description: A precursor solution, (0.5 M), was made by mixing CsBr (Sigma Aldrich, 0.21 grams), PbBr2 (Sigma Aldrich, 0.37 grams), and dimethyl sulfoxide (DMSO) (2 mL). This solution was then spin cast at 3000 RPM on cleaned glass for 60 seconds. It was then annealed at 106 °C for 20 minutes. The resulting film of CsPbBr3 was about 100 nm thick.
Method: Photoluminescence measurement at T = 100 K
Description: The CsPbBr3 thin film is excited at 447 nm with power at 0.5 mW and the intensity of each photon energy emission is measured. This test was performed at temperature T = 100 K.