Layer-edge device of two-dimensional hybrid perovskites

Abstract

Two dimensional layered organic-inorganic hybrid perovskites (2D perovskites) are potential candidates for next generation photovoltaic device. Especially, the out-of-plane surface perpendicular to the superlattice plane of 2D perovskites (layer-edge surface) has presented several exotic behaviors, such as layer-edge states which are found to be crucial for improving the efficiency of 2D perovskite solar cells. However, fundamental research on transport properties of layer-edge surface is still absent. In this report, we observe the electronic and opto-electronic behavior in layer-edge device of 2D perovskites. The dark and photo currents are demonstrated to strongly depend on the crystallographic orientation in layer-edge device, and such anisotropic properties, together with photo response, are related to the thickness of inorganic layers. Finally, due to the abundant hydroxyl groups, water molecules are easy to condense on the layer-edge surface, and the conductance is extremely sensitive to the humidity environment, indicating a potential application of humidity sensor.

Tunable self‐powered n‐SrTiO3 photodetectors based on varying CuS‐ZnS nanocomposite film (p‐CuZnS, p‐CuS, and n‐ZnS)

“…Photodetectors, which detect irradiation directly by transforming light into electrical signals based on photoelectric effect, have been extensively used in various applications, such as environmental monitoring, biological/chemical analysis, flame detection, and communications . Recently, many groups are dedicated to realizing photodetectors with self‐powered characteristics .…”

“…Photodetectors, which detect irradiation directly by transforming light into electrical signals based on photoelectric effect, have been extensively used in various applications, such as environmental monitoring, biological/chemical analysis, flame detection, and communications. [1][2][3][4][5][6][7] Recently, many groups are dedicated to realizing photodetectors with self-powered characteristics. [8][9][10][11][12] The self-powered devices can work under zero bias due to the photovoltaic effect from p-n junctions or heterojunctions under light illumination, and are particularly appealing for their miniaturization and portability.…”

Manipulation of charge carrier flow in Bi4NbO8Cl nanoplate photocatalyst with metal loading

“… 20 However, from the viewpoint of efficient charge separation inside the photocatalysts, two-dimensional crystal structures may be unfavorable because both photoexcited electrons and holes travel mainly along the in-plane direction, as observed theoretically 21–24 and experimentally. 25–27 Such parallel carrier flows based on the crystal and band structure make it difficult to separate the oxidation and reduction reaction sites in the photocatalyst particles, often resulting in charge recombination. Although the reduction and oxidation sites on several layered photocatalysts such as BaLa 4 Ti 4 O 15 were separated, 13,28 the underlying carrier flows in the bulk of the photocatalysts remain elusive.…”

Electronic and Optical Properties of van der Waals Heterostructures Based on Two-Dimensional Perovskite (PEA)2PbI4 and Black Phosphorus

“…2D RP perovskite materials have the general chemical formula A 2 BX 4 and comprise stacks of octahedral metal–halide (B–X) monolayers, where B is normally a divalent metal, each isolated by long-chain organic molecules (A) to maintain charge balance. − In the 2D hybrid perovskites, it requires more energy to destroy the 2D crystal structure due to the large van der Waals (vdW) interaction between organic cations and inorganic anions, which leads to excellent stability contrasting to their 3D counterparts , Furthermore, 2D perovskites not only enjoy benefits of molecular scale self-assembly, soluble processing, and excellent film formation but also have advantages of excellent optical properties and large carrier diffusion length. − Tsai et al fabricated nearly single crystalline 2D perovskite (BA) 2 PbI 4 with an efficiency of about 12% when used as a solar absorber, indicating that 2D perovskites exhibit superior stability . At the same time, the organic insulating layer also causes the quantum confinement effect, which widens the energy band gap of the 2D material, increases the exciton binding energy, and weakens the optical absorption.…”