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.
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.
Starting materials: PbI2, toluene, butyric acid, butylamine, butylammonium iodide, anhydrous acetonitrile
Product: Thin 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 solid material was dissolved in acetonitrile to a desired concentration and then was spin-coated onto a glass substrate at 3000 rpm for 30 seconds.
Method: Photoluminescence Spectra
Description: A Horiba-Jobin Yvon Fluorolog-3 instrument was used on the films to measure photoluminescence spectra. Excitation was perpendicular to the film 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.
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: Photoluminescence
Description: Recorded on FLS 980 (Edinburgh Instruments).