Crystal system: monoclinic
| a: | 17.4586 Å |
| b: | 9.2513 Å |
| c: | 8.586403313 Å |
| α: | 90° |
| β: | 103.2228064° |
| γ: | 90° |
Starting materials: 2-Aminoheptane (1-Me-ha, 99%), hydriodic acid (HI) solution (57 wt%, stabilized, 99.95%), PbI2
Product: Clear light orange plate-like crystals
Description: 1Me-ha∙HI salt was synthesized by adding a stoichiometric volume of HI into 2-Aminoheptane in a cold water bath, evaporating water at 150 ˚C on a hot plate and vacuum drying at 150 ˚C at 40 mtorr for a week. Thin plate-like (1-Me-ha)2PbI4 crystals were grown by adding stoichiometric amounts of PbI2 (0.25 mmol) and 1-Me-ha∙HI (0.5 mmol) to a solution of 0.5 mL HI solution and 0.5 mL methanol followed by slow evaporation of the solution over a week. The crystals were filtered and washed with ethyl ether.
Method: Single crystal X-ray Diffraction
Description: Data were collected using Bruker D8 ADVANCE Series II diffractometer using Mo Kα radiation (= 0.71073 Å).
See all entries for this property (2 total)
Crystal system: unknown
| Band gap (fundamental), eV |
|---|
Starting materials: PbO, HI, H3PO2, heptylamine
Product: spin-coated thin film
Description: First step: (C7)2PbI4 single crystal flakes synthesized as follows: Slow-cooling in HI method: 2.232g (10 mmol) of PbO dissolved in glass vial containing 10 mL of HI and 1.7 mL of H3PO2. Brought to near-boiling temperature. 10 mmol of the organic amine mixed with 5 mL HI, cooled in an ice bath. Solutions were mixed and heated, then cooled to room temperature, upon which single crystal flakes form. Crystals were then washed thrice with diethyl ether and dried under a vacuum. Second step (thin film formation): Flakes were dissolved in 4:1 DMF:DMSO solvent mixture, stirred for 30 minutes. Substrate: quartz substrate with 120 nm gold layer of interdigitated fingers. Precursor solution (0.1-0.3 molar) pipetted onto substrate and then spun at 4000 rpm for 30 seconds, targeting film thickness of 80-300nm. Film was solvent-annealed, then enclosed with 2mL dH2O. When the crystallites were cooled to low temperature, a portion remained in phase I structure, allowing for simultaneous measurements in phase I and II structures.
Method: Electroabsorption
Description: Films were spin-coated onto interdigitated Au electrode array - 45 micron distance between opposing fingers. Samples mounted in cryostat with Cu wires soldered to opposing electrode stripes. Xe lamp light spectrally filtered, focused on sample and subsequently on UV-enhanced Si photodiode detector. Sample transmission, substrate transmission, and sample electrotransmission were collected in independent scans.Absorbance and electroabsorbance were then calculated from the respective transmissions. The fundamental gap is determined by the crossover point of absorption curves measured under different electric fields in the fundamental band gap region.
Comment: Significantly more detail in paper.
See all entries for this property (2 total)
Crystal system: unknown
| Exciton binding energy, eV |
|---|
Starting materials: PbO, HI, H3PO2, heptylamine
Product: spin-coated thin film
Description: First step: (C7)2PbI4 single crystal flakes synthesized as follows: Slow-cooling in HI method: 2.232g (10 mmol) of PbO dissolved in glass vial containing 10 mL of HI and 1.7 mL of H3PO2. Brought to near-boiling temperature. 10 mmol of the organic amine mixed with 5 mL HI, cooled in an ice bath. Solutions were mixed and heated, then cooled to room temperature, upon which single crystal flakes form. Crystals were then washed thrice with diethyl ether and dried under a vacuum. Second step (thin film formation): Flakes were dissolved in 4:1 DMF:DMSO solvent mixture, stirred for 30 minutes. Substrate: quartz substrate with 120 nm gold layer of interdigitated fingers. Precursor solution (0.1-0.3 molar) pipetted onto substrate and then spun at 4000 rpm for 30 seconds, targeting film thickness of 80-300nm. Film was solvent-annealed, then enclosed with 2mL dH2O. When the crystallites were cooled to low temperature, a portion remained in phase I structure, allowing for simultaneous measurements in phase I and II structures.
Method: Electroabsorption
Description: Films were spin-coated onto interdigitated Au electrode array - 45 micron distance between opposing fingers. Samples mounted in cryostat with Cu wires soldered to opposing electrode stripes. Xe lamp light spectrally filtered, focused on sample and subsequently on UV-enhanced Si photodiode detector. Sample transmission, substrate transmission, and sample electrotransmission were collected in independent scans. Absorbance and electroabsorbance were then calculated from the respective transmissions. The exciton binding energy arises as the difference of the 1s exciton peak energy observed in conventional absorption and the fundamental gap as determined by the crossover point of absorption curves measured under different electric fields in the fundamental band gap region.
Comment: Significantly more detail in paper.
See all entries for this property (2 total)
Crystal system: unknown
| Exciton energy, eV |
|---|
Starting materials: PbO, HI, H3PO2, heptylamine
Product: spin-coated thin film
Description: First step: (C7)2PbI4 single crystal flakes synthesized as follows: Slow-cooling in HI method: 2.232g (10 mmol) of PbO dissolved in glass vial containing 10 mL of HI and 1.7 mL of H3PO2. Brought to near-boiling temperature. 10 mmol of the organic amine mixed with 5 mL HI, cooled in an ice bath. Solutions were mixed and heated, then cooled to room temperature, upon which single crystal flakes form. Crystals were then washed thrice with diethyl ether and dried under a vacuum. Second step (thin film formation): Flakes were dissolved in 4:1 DMF:DMSO solvent mixture, stirred for 30 minutes. Substrate: quartz substrate with 120 nm gold layer of interdigitated fingers. Precursor solution (0.1-0.3 molar) pipetted onto substrate and then spun at 4000 rpm for 30 seconds, targeting film thickness of 80-300nm. Film was solvent-annealed, then enclosed with 2mL dH2O. When the crystallites were cooled to low temperature, a portion remained in phase I structure, allowing for simultaneous measurements in phase I and II structures.
Method: Electroabsorption
Description: Films were spin-coated onto interdigitated Au electrode array - 45 micron distance between opposing fingers. Samples mounted in cryostat with Cu wires soldered to opposing electrode stripes. Xe lamp light spectrally filtered, focused on sample and subsequently on UV-enhanced Si photodiode detector. Sample transmission, substrate transmission, and sample electrotransmission were collected in independent scans. Absorbance and electroabsorbance were then calculated from the respective transmissions.
Comment: Significantly more detail in paper.