See all entries for this property (3 total)
Crystal system: orthorhombic
| a: | 8.8632 (±0.0021) Å |
| b: | 8.6816 (±0.0008) Å |
| c: | 27.57 (±0.002) Å |
| α: | 90° |
| β: | 90° |
| γ: | 90° |
Starting materials: PbI2, HI, C4H9NH2
Product: Orange-yellow sheetlike crystals
Description: Grow the crystals under slowly-cooled aqueous hydriodic acid solutions. Perform all synthetic steps and crystal manipulations after synthesis in an inert atmosphere to prevent oxidation. Dissolve 0.534 g (1.16 mmol) of PbI2 in 2 mL of concentrated (57 wt %) aqueous HI solvent under flowing argon at 90 °C. In a separate tube, dissolve 2.32 mmol of (C4H9NH2).HI in 3 mL of concentrated HI solution and add to the metal halide solution. Ramp the solution temperature at 2 °C/h from 90 to -10 °C, filter the crystals formed under argon or nitrogen and dry in argon at 80 °C.
Method: Single crystal X-ray diffraction
Description: Select suitable single crystals in an argon-filled drybox (<1 ppm O2 and H2O) under a microscope and seal in quartz capillaries. Collect data at room temperature on an Enraf-Nonius CAD4 diffractometer with graphite-monochromatized Mo Ka radiation. Obtain unitcell parameters and the crystal orientation matrix by a least-squares fit of 25 reflections with 18° < 2θ < 30°. Monitor intensity control reflections every 5000s during the data collection. Little to no degradation was observed for the compounds. Use the NRCVAX 386 PC version program for structural solution and refinement.
Crystal system: orthorhombic
| Band gap (optical, diffuse reflectance), eV |
|---|
Starting materials: PbI2, toluene, butyric acid, butylamine, butylammonium iodide
Product: Powder film on glass substrate
Description: PbI2, butyric acid, toluene, and butylamine were mixed in a capped flask. Separately, butylammonium iodide was dissolved in toluene with butylamine and butyric acid. The two solutions were combined and stirred until an insoluble yellow solid precipitated. The solid was removed by centrifuging at 6000 rpm for 3 minutes. The yellow solid was redispersed in toluene and centrifuged a second time, to produce the final products. The paintlike paste was then deposited on a glass substrate. A Pasteur pipette was used to spread the paste over the surface and was then allowed to dry.
Method: Diffuse reflectance spectra
Description: Diffuse reflectance spectra were measured in a Shimadzu UV 2450 instrument. A Ba2SO4 powder palette was the reference used. The reflectance was converted to absorbance.
See all entries for this property (2 total)
Crystal system: orthorhombic
| Photoluminescence peak position, nm |
|---|
Starting materials: PbI2, toluene, butyric acid, butylamine, butylammonium iodide
Product: Powder film on glass substrate
Description: PbI2, butyric acid, toluene, and butylamine were mixed in a capped flask. Separately, butylammonium iodide was dissolved in toluene with butylamine and butyric acid. The two solutions were combined and stirred until an insoluble yellow solid precipitated. The solid was removed by centrifuging at 6000 rpm for 3 minutes. The yellow solid was redispersed in toluene and centrifuged a second time, to produce the final products. The paintlike paste was then deposited on a glass substrate. A Pasteur pipette was used to spread the paste over the surface and was then allowed to dry.
Method: Photoluminescence spectra
Description: A Horiba-Jobin Yvon Fluorolog-3 instrument was used on the powder films to measure photoluminescence spectra. Excitation was perpendicular to the sample and emission was collected at an angle of ~15 degrees. The data was corrected according to the lamp and detector details by using algorithms from the equipment software.
See all entries for this property (3 total)
Starting materials: lead oxide (10 mmol), hydriodic acid (10 mL), hypophosphorous acid (1.7 mL ), C4H9NH3I
Product: (BA)2PbI4
Description: Single crystals of (BA)2PbI4 were synthesized in a method called acid precipitation. Through constant stirring and heating, lead oxide (10 mmol) was dissolved in a solution that contained hydriodic acid (10 mL) and hypophosphorous acid (1.7 mL). After, C4H9NH3I was added to the mixture, causing the bright yellow solution to change to an orange color precipitate. Continuous heating of the mixture followed until the precipitate was fully dissolved, forming orange crystals at room temperature. The crystals were obtained via filtration and bathed in diethyl ether.
Method: UV-visible absorption
Description: Optical diffuse-reflectance spectra were collected at room temperature using a Shimadzu UV-3600 plus UV-VIS-NIR spectrophotometer. The reflectance spectra were converted to absorbance by using the Kubelka-Munk transformation; (α/S = (1 − R)^2/2R); α is the absorption coefficient, S is the scattering coefficient, and R is the reflectance.
See all entries for this property (2 total)
Crystal system: unknown
| Band gap (fundamental), eV |
|---|
Starting materials: PbO, HI, H3PO2, butylamine
Product: spin-coated thin film, high crystallinity
Description: For BA2PbI4 (I): First step: BAPbI4 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. For BA2PbI4 (I), solution was cooled to ~80 deg C, upon which crystals began to form and left undisturbed for three days. Afterwards, crystals were slowly cooled to room temperature (rate: 2 deg C/hr). Some crystallites in the film were found in the RT (I) phase and others found in the low-temperature (II) phase. 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 (0.05-0.1 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.
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, butylamine
Product: spin-coated thin film, high crystallinity
Description: For BA2PbI4 (I): First step: BAPbI4 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. For BA2PbI4 (I), solution was cooled to ~80 deg C, upon which crystals began to form and left undisturbed for three days. Afterwards, crystals were slowly cooled to room temperature (rate: 2 deg C/hr). Some crystallites in the film were found in the RT (I) phase and others found in the low-temperature (II) phase. 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 (0.05-0.1 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.
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. 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 energy, eV |
|---|
Starting materials: PbO, HI, H3PO2, butylamine
Product: spin-coated thin film, high crystallinity
Description: For BA2PbI4 (I): First step: BAPbI4 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. For BA2PbI4 (I), solution was cooled to ~80 deg C, upon which crystals began to form and left undisturbed for three days. Afterwards, crystals were slowly cooled to room temperature (rate: 2 deg C/hr). Some crystallites in the film were found in the RT (I) phase and others found in the low-temperature (II) phase. 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 (0.05-0.1 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.
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.
See all entries for this property (4 total)
Starting materials: PbI2, HI, C4H9NH2
Product: Orange-yellow sheetlike crystals
Description: Grow the crystals under slowly-cooled aqueous hydriodic acid solutions. Perform all synthetic steps and crystal manipulations after synthesis in an inert atmosphere to prevent oxidation. Dissolve 0.534 g (1.16 mmol) of PbI2 in 2 mL of concentrated (57 wt %) aqueous HI solvent under flowing argon at 90 °C. In a separate tube, dissolve 2.32 mmol of (C4H9NH2).HI in 3 mL of concentrated HI solution and add to the metal halide solution. Ramp the solution temperature at 2 °C/h from 90 to -10 °C, filter the crystals formed under argon or nitrogen and dry in argon at 80 °C.
Method: Photoluminescence
Description: Collect the photoluminescence spectra within several hours after the crystals were synthesized, and maintain the samples in an argon-filled cell during measurement to prevent degradation. The photoluminescence spectra were excited by 457.9 nm (2.71 eV) light from an argon ion laser. This light was strongly absorbed by each sample, ensuring that the observed luminescence came from the front side of the samples. The excitation density was below 1 W cm-2. Refer to Page 794 for details.