Starting materials: PbI2, toluene, butyric acid, butylamine, formamidinium acetate
Product: Powder film on glass substrate
Description: PbI2, toluene, butyric acid, and butylamine were mixed in a capped flask. Separately, formamidinium acetate was dissolved in toluene and butyric acid. The solutions are combined and stirred until a red solid precipitated. The solid was removed by centrifuging at 6000 rpm for 3 minutes. It was then re-dispersed in hexane and centrifuged again to obtain the final paintlike paste. 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 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: PbI2, toluene, butyric acid, butylamine, formamidinium acetate
Product: Thin film on glass substrate
Description: PbI2, toluene, butyric acid, and butylamine were mixed in a capped flask. Separately, formamidinium acetate was dissolved in toluene and butyric acid. The solutions are combined and stirred until a red solid precipitated. The solid was removed by centrifuging at 6000 rpm for 3 minutes. It was then re-dispersed in hexane and centrifuged again to obtain the final paintlike paste. 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: PbO (99.9%), FA acetate, hydroiodic acid (HI, 57 wt % in H2O, distilled, stabilized, 99.95%), butylamine, hypophosphorous acid solution (H3PO2, 50 wt % in H2O)
Product: red plate-shaped crystals
Description: First, PbO (223 mg, 1 mmol) and FA acetate (52.1 mg, 0.5 mmol) were added to 1.5 mL of concentrated HI solution. These substances were dissolved under constant stirring and heating. Then, BA (89.1 μL, 0.9 mmol) was added to 0.25 mL of concentrated aqueous H3PO2 in a separate vial. This solution was stirred and was soon added to the initial solution. The temperature was lowered to 125º C until crystals began to form. The temperature was lowered again to 80ºC, the hot plate was turned off after 60 minutes, and after 30 minutes thereafter, the crystals were collected.
Method: Photoluminescence microscopy
Description: A Horiba LabRAM HR Evolution confocal Raman microscope was used with a 473 nm laser to excite samples at 50x magnification.