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Organic frameworks (OFs) offer a novel strategy for assembling organic semiconductors into robust networks that facilitate transport, especially the covalent organic frameworks (COFs). However, poor electrical conductivity through covalent bonds and insolubility of COFs limit their practical applications in organic electronics. It is known that the two-dimensional intralayer π∙∙∙π transfer dominates transport in organic semiconductors. However, because of extremely labile inherent features of noncovalent π∙∙∙π interaction, direct construction of robust frameworks via noncovalent π∙∙∙π interaction is a difficult task. Toward this goal, we report a robust noncovalent π∙∙∙π interaction-stacked organic framework, namely πOF, consisting of a permanent three-dimensional porous structure that is held together by pure intralayer noncovalent π∙∙∙π interactions. The elaborate porous structure, with a 1.69-nm supramaximal micropore, is composed of fully conjugated rigid aromatic tetragonal-disphenoid-shaped molecules with four identical platforms. πOF shows excellent thermostability and high recyclability and exhibits self-healing properties by which the parent porosity is recovered upon solvent annealing at room temperature. Taking advantage of the long-range π∙∙∙π interaction, we demonstrate remarkable transport properties of πOF in an organic-field-effect transistor, and the mobility displays relative superiority over the traditional COFs. These promising results position πOF in a direction toward porous and yet conductive materials for high-performance organic electronics.

Photodetectors are widely used in various fields, such as industrial manufacturing and military defense. Researchers have recently sought a photodetector that combines high polarization sensitivity and a robust optical response. As an anisotropic semiconductor material, SnS holds potential for photodetection across the visible light spectrum. This study employs first-principles density functional theory (DFT) along with the non-equilibrium Green's function (NEGF) method to theoretically investigate the optoelectronic properties of the SnS monolayer in two device orientations: Armchair and Zigzag. It is found that the maximum photocurrent values between the two orientations are small at zero bias voltage, and stable photocurrent can be obtained by adding bias voltage. We examine the maximum photocurrent variation under linearly polarized light irradiation within a small bias voltage range (0.1 to 1.0 V), found for the maximum photoresponse of monolayer SnS to be large and stable at photon energy of 2.4 and 3.2 eV, and analyze the underlying mechanism of photoresponse, employing energy band and density of state diagrams. Additionally, we have calculated the extinction ratio of the SnS monolayer, confirming its strong polarization sensitivity. Finally, by subjecting the device to biaxial strain, we significantly speculate to enhance its asymmetry, leading to a substantial increase in photocurrent at zero bias. A compressive strain of - 6% notably increases the photocurrent. These findings offer valuable theoretical insights for the design of SnS monolayers as photodetectors. [ABSTRACT FROM AUTHOR]

Organic frameworks (OFs) offer a novel strategy for assembling organic semiconductors into robust networks that facilitate transport, especially the covalent organic frameworks (COFs). However, poor electrical conductivity through covalent bonds and insolubility of COFs limit their practical applications in organic electronics. It is known that the two-dimensional intralayer [pi]***[pi] transfer dominates transport in organic semiconductors. However, because of extremely labile inherent features of noncovalent [pi]***[pi] interaction, direct construction of robust frameworks via noncovalent [pi]***[pi] interaction is a difficult task. Toward this goal, we report a robust noncovalent [pi]***[pi] interaction-stacked organic framework, namely [pi]OF, consisting of a permanent three-dimensional porous structure that is held together by pure intralayer noncovalent [pi]***[pi] interactions. The elaborate porous structure, with a 1.69-nm supra-maximal micropore, is composed of fully conjugated rigid aromatic tetragonal-disphenoid-shaped molecules with four identical platforms. [pi]OF shows excellent thermostability and high recyclability and exhibits self-healing properties by which the parent porosity is recovered upon solvent annealing at room temperature. Taking advantage of the long-range [pi]***[pi] interaction, we demonstrate remarkable transport properties of [pi]OF in an organic-field-effect transistor, and the mobility displays relative superiority over the traditional COFs. These promising results position [pi]OF in a direction toward porous and yet conductive materials for high-performance organic electronics. COFs | field-effect transistor | organic conductor