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.