Mesoscale Growth and Assembly of Bright Luminescent Organolead Halide Perovskite Quantum Wires

Abstract

S1. Spectroscopy characterization1 H NMR and FTIR characterization. The 1 H NMR spectra were obtained with a Bruker AVANCE III 500 instrument at 500 MHz frequency. Typically ~10-15 mg of purified sample were dissolved in 0.6 mL of chloroform-d at room temperature. A minimum of 1024 scans were collected with a 30° pulse angle, 3.17 sec of acquisition, and 3 sec of relaxation. All data were plotted via TOPSPIN 2.1 software. The FTIR measurements were taken using a Thermo Nicolet IS10 FT-IR spectrometer. For FT-IR analysis, samples were prepared by placing a 10 µL dissolved sampled on a KBr salt plate. A minimum of 128 scan was collected and all data were processed using Omnic FTIR software.Energy dispersive X-ray (EDX) analysis. EDX analysis was performed using a Hitachi S-4700 field-emision scanning electron microscope. The measurements were conducted at a pressure <5 x10 -9 Torr. For XPS analysis, the CH 3 NH 3 PbBr 3 quantum wires were drop-casted on a piranha-cleaned silicon wafer inside a N 2 filled glove box, and the solution was allowed to evaporate at room temperature. The piranha-cleaned silicon wafer had been washed with a copious amount of Nanopure water and ethanol, and then dried in a vacuum oven at 120 °C over night. The XPS analysis was performed for two different batches of CH 3 NH 3 PbBr 3 quantum wires and five randomly selected area. (Warning: piranha solution is highly reactive and must be handled with extreme caution. It reacts violently with organic materials and may not be stored in tightly closed vessels). X-ray photoelectron spectroscopy (XPS) analysis.All XPS spectra were collected on a Kratos Axis Ultra DLD system with a Mg anode at 1253.6 eV and X-ray power of 150 W. A charge neutralizer was used to prevent charging. The survey scans were collected over binding energies of 0-1000 eV with a 80 eV pass energy. For high resolution scans of Pb(4f), Br(3d), and N(1s), a 20 eV pass energy was used. All data were collected so that the C 1s line was shifted to 284.6 eV. The samples were prepared as described for EDX analysis. Here, two different batches of CH 3 NH 3 PbBr 3 quantum wires were analyzed over five randomly selected areas in each.Powder X-ray diffraction (XRD) analysis. Wide-angle XRD was recorded on a Rigaku MiniFlex™ II (Cu Kα) instrument. Sample was prepared by dropcasting the purified quantum wires on a piranha cleaned glass coverslips. S2. Characterization data (Fig. S1 to Fig. S13)

Peptide‐Passivated Lead Halide Perovskite Nanocrystals Based on Synergistic Effect between Amino and Carboxylic Functional Groups

“…The Br 3d 5/2 and Br 3d 3/2 peaks were observed at 67.6 and 68.5 eV for bulk materials. [6,14] Furthermore, the surface atom ratio (Br -/Pb 2+ ) increased from 3.1 to 3.4 when peptides were used as capping ligands (Table 1), as an indication of Brrich surface for PNC, which is in agreement with other studies.…”

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17] These properties are only when both amino and carboxylic functional groups were present at the same time, and this can be accomplished using single peptide molecules. [4][5][6][7][8][9][10][11][12][13][14][15][16][17] These properties are only when both amino and carboxylic functional groups were present at the same time, and this can be accomplished using single peptide molecules.…”

Lead Halide Perovskite Nanocrystals: Stability, Surface Passivation, and Structural Control

“…By using a similar solvent/antisolvent strategy, the combination of branched capping ligands with amine functional groups and oleic acid have been successfully applied in the surface passivation of MAPbBr 3 PNCs, which exhibit good uniformity and high QY (55 %) . Subsequently, several studies have found that the combination of amino ligands and carboxylic ligands is effective in stabilizing and passivating different types of PNCs . Stable PNCs with high QY can be obtained only when both ligands are used, indicating synergistic effects between the two ligands.…”

“…Structural control is important for semiconductor NCs, as shapes and sizes can affect their physical and chemical properties as a result of possible changes in band structure. Various strategies have been reported for controlling the size and shape of PNCs, including varying the reaction temperature and time during synthesis . In addition, capping ligands with different structures and lengths can also affect the nucleation and growth rate owing to their anchoring and steric effects, and thereby the structure of NCs, as has been demonstrated in the synthesis of different dimensional PNCs .…”

“…Recently, efforts have been made to make 1D or 2D PNCs. For example, Teunis's group proposed a colloidal synthetic approach to prepare 1D CH 3 NH 3 PbBr 3 perovskite nanowires (PNWs) induced by van der Waals interactions and chain interdigitation of the capping ligands (Figure d) . Yuan et al.…”