Advances in two-dimensional organic–inorganic hybrid perovskites

Abstract

Recent achievements of 2D perovskites for various optoelectronic applications along with their basic properties and future opportunities are discussed.

Water‐Assisted Crystal Growth in Quasi‐2D Perovskites with Enhanced Charge Transport and Photovoltaic Performance

“…The general formula of RP‐2D perovskites takes the form of (L) 2 A n −1 Pb n I 3 n +1 ( n = 1, 2, 3, 4…) where A is the methylammonium (MA + ), formamidinium (FA + ), or cesium (Cs + ) cations, L is the bulky organic ligands, e.g., butylammonium (BA + ) or 2‐phenylethylammonium (PEA + ), and n is the number of layers in the [PbI 6 ] 4− octahedral sheets. [ 4–7 ] The incorporation of hydrophobic bulky organic ligands can not only enhance the stability of perovskites with minimized permeation of water molecules but also increase the formation energy of perovskites to mitigate thermal degradation and ion migration. [ 8–10 ] These merits alongside the quantum confinement have rendered quasi‐2D perovskites great potentials for optoelectronic applications with a wide tunability on the bandgap or photophysical properties.…”

“…[ 8–10 ] These merits alongside the quantum confinement have rendered quasi‐2D perovskites great potentials for optoelectronic applications with a wide tunability on the bandgap or photophysical properties. [ 7 ] Unfavorably, quasi‐2D perovskites are generally associated with a large exciton binding energy (hundreds of meV) due to the insulating nature of bulky organic ligands and the specific layered arrangement. [ 11,12 ] As a result, charge transport and extraction are hindered in quasi‐2D PSCs.…”

Influence of the Vibrational Modes from the Organic Moieties in 2D Lead Halides on Excitonic Recombination and Phase Transition

“…2D metal halides are materials that have been receiving increasing attention in the past few years. [ 1–4 ] Owned for their unique optoelectronic properties, these semiconductors are prominent in the development of a series of new‐generation photonic devices such as solar cells, [ 5–8 ] LEDs, [ 9–11 ] and photodetectors. [ 12–14 ] Their structure is commonly compared to 3D metal halide perovskites with structure ABX 3 (where A is monovalent cation, B is a divalent cation, more frequently Pb 2+ and Sn 2+ , and X is a halide different from F − ) and, very commonly, are regarded as reduced dimensional perovskites or 2D perovskites.…”

2D Materials and Heterostructures at Extreme Pressure

“…[58] In the past decade, a majority of 2D ultrathin materials involving transition metal dichalcogenides (TMDs, e.g., MoS 2 , MoSe 2 , WSe 2 , WS 2 , TiS 2 , TaS 2 , etc. ), [49,[59][60][61] BN, [21][22][23][24][25][26]35,[62][63][64][65][66][67][68][69][70][71] BP, [72][73][74][75][76][77][78][79][80][81][82][83][84] 2D organic crystals (e.g., 2D small molecular and polymers), [85][86][87][88][89][90][91][92][93][94][95] 2D perovskites, [96][97][98][99]…”