Quantum and Dielectric Confinement Effects in Lower-Dimensional Hybrid Perovskite Semiconductors

Abstract

A c c e p t e d M a n u s c r i p t octahedra linked together either by Pb 2+ ions (blue octahedra), in (PPA)Pb 2 I 7 (PPA + = phenylpropylammonium) (left) and (PBA)Pb 2 I 7 (PBA + = phenylbutylammonium) (middle), or through edge-sharing mode in (H 2 Aepz) 3 Pb 4 I 14 (Aepz = 2-(2-aminoethyl)-pyrazole) (right). Adjacent ribbons appear as light pink octahedra and pink octahedra. 2.2. Formation of perovskite networks / choice of organic cations 2.2.1. (EDBE : 2,2'-(ethylenedioxy)bis(ethylammonium)) (c) and (H 2 D2c) 2 Pb 2 Br 8 (H2D2c : N-methylethane-1,2diammonium) (d) showing the hydrogen bonding at the organic-inorganic interface. 2.3. Multilayered <100>-oriented perovskites 2.3.1.

Multilayered 2D Cesium‐Based Hybrid Perovskite with Strong Polarization Sensitivity: Dimensional Reduction of CsPbBr3

“…1D nanowires) or intrinsic anisotropy of the crystal structure (e.g. 2D anisotropic materials) . However, the 3D perovskite motif of CsPbBr 3 exhibits isotropic structural characteristics, while the only existing pathway is to pattern extrinsically oriented anisotropic devices using 1D nanowires that greatly restrict the practical applications .…”

“…In principle, the anisotropy of electrical characteristics derives from the alternating stacking of organic and inorganic components in the structure. This special configuration promotes that the transport of charge maintains superior in the crystal lattice direction of the inorganic skeletons than in the direction perpendicular to the crystal lattice of the inorganic skeletons …”

Reversible Thermochromism and Strong Ferromagnetism in Two‐Dimensional Hybrid Perovskites

“…The band gap of each quantum‐well is mainly determined by the number of inorganic monolayer sheets within a layered perovskite . The MQW electronic structure enables 2D halide perovskite particularly interesting for optoelectronic applications and magnetic studies . Magnetic susceptibility was investigated in Cs 4 Mn 1− x Cu x Sb 2 Cl 12 ( x =0–1), which were dependent on the concentration of manganese and copper .…”

Manipulation of Dipolar Polarization at Steady States for a Quasi‐2D Organic–Inorganic Hybrid Perovskite with a Nanorod Network

“…Entirely layered 2D perovskite structures are built by sequential quantum wells with the chemical formula , in which A denotes a long chain of organic molecules, is a disordered small organic cation in the 3D framework, M and X represent a divalent metal cation and a halide anion, respectively, and n determines the number of layers of the octahedral . The structures feature strong quantum and dielectric confinements, leading to relatively larger bandgaps and binding energies depending on the value of n . Due to the enhancement of the binding energies for electron–hole recombination, they were more preferentially applied for perovskite light‐emitting devices (PeLEDs) at the beginning .…”

“…The pure 2D configuration eliminates the photovoltaic effect because of the tradeoff between device stability and efficient free‐charge‐carrier transport. One feasible way is to fabricate a quasi‐2D structure, mixing 2D and 3D OIHPs . Within the structure, the additionally long organic chain plays the dominant role in preventing OIHP degradation, and the crystalline framework of the 3D perovskite is mainly responsible for efficient electron–hole dissociation and free‐charge‐carrier transport.…”