Regulating the Intermolecular Hydrogen Bond to Realize Directional Dimension Reduction of Lead Iodide Perovskite toward Low-Dimensional Photovoltaics

Abstract

A low-dimensional organic amine lead halide perovskite is an attractive semiconductor material that has potential application prospects in photovoltaics, light-emitting diodes, detectors, X-ray imaging, and other fields. It has been reported that the photoelectric properties of low-dimensional perovskite can be controlled by adjusting the chain length of organic ammonium, the ratio of precursor components, and van der Waals interaction between amine molecules. Herein, we report the successful synthesis of low-dimensional perovskite (PdEA)PbI 4 (PdEA = piperidine ethylammonium) and (MlEA)PbI 4 (MlEA = morpholine ethylammonium) single crystals by regulating the intermolecular hydrogen bond of organic ammonium ligands. The two-dimensional (2D) layered structure (PdEA)PbI 4 single crystal with a fluorescence reflection peak at 563 nm was produced by the reaction of PdEA with PbO in a concentrated hydroiodic acid aqueous solution. Differently, the (MlEA)PbI 4 single crystal prepared by replacing MlEA with PdEA presents a one-dimensional (1D) rod structure, and its fluorescence reflection peak is located at 531 nm. The optical bandgaps of (PdEA)PbI 4 and (MlEA)PbI 4 perovskite films were about 2.16 and 2.33 eV, respectively. Low-dimensional perovskite solar cells with 2D (PdEA)PbI 4 and 1D (MlEA)PbI 4 of perovskite films yielded efficiencies of 1.18 and 1.52%, respectively.

Approaching Full-Scale Passivation in Perovskite Solar Cells via Valent-Variable Carbazole Cations

“…17−19 Previously, we reported two nitrogen-containing heterocyclic LSOCs, piperidine ethylammonium (PdEA) and morpholine ethylammonium (MlEA), revealing that intermolecular interactions (e.g., hydrogen bonding) among organic cations could significantly influence the arrangement of perovskite frameworks from layered 2D (PdEA)PbI 4 to rodlike 1D (MlEA)PbI 4 . 20 Notably, these two LSOCs demonstrated divalent states in crystallographic analysis, different from most monovalent LSOCs reported. Therefore, herein we designed carbazole ethylammonium (CzEA, chemical structure shown in Figure 1a), which contained a large planar nitrogen-containing conjugated unit and should induce strong π−π stacking behaviors to control the perovskite framework arrangement.…”

“…Previously, we reported two nitrogen-containing heterocyclic LSOCs, piperidine ethylammonium (PdEA) and morpholine ethylammonium (MlEA), revealing that intermolecular interactions (e.g., hydrogen bonding) among organic cations could significantly influence the arrangement of perovskite frameworks from layered 2D (PdEA)­PbI 4 to rodlike 1D (MlEA)­PbI 4 . Notably, these two LSOCs demonstrated divalent states in crystallographic analysis, different from most monovalent LSOCs reported.…”

Novel C3N4-Assisted Bilateral Interface Engineering for Efficient and Stable Perovskite Solar Cells

“…Similar to the front interface modification, three perovskite films exhibit similar diffraction peaks, which suggest the negligible influence of C 3 N 4 -induced back interface modification toward the crystal structure of perovskite. 38,39 Differently, the y-CN-modified perovskite film exhibits the strongest diffraction peak intensity of the (200) plane in comparison to the other two films, and the corresponding fwhm is 0.151°, smaller than those of control (0.230°) and w-CN-modified (0.191°) films (Figure 5c). SEM images are also carried out to study the CsPbIBr 2 film quality (panels d−f of Figure 5).…”

Understanding and Controlling the Photoluminescence Line Shapes of 2D Perovskites with Chiral Methylbenzylammonium-Based Cations

“…Furthermore, the presence of the −OMe group increases the dipole moment on the molecule. This feature facilitates the end-to-end selfassembly of the molecules through H-bonding, 46 which may facilitate the assembly of 2D structures. Nevertheless, further research is required to elucidate all of the complex intricacies of crystallization and film formation in this case.…”