Fused‐Ring Electron‐Acceptor Single Crystals with Chiral 2D Supramolecular Organization for Anisotropic Chiral Optoelectronic Devices

Abstract

Supramolecular chiral organization gives π‐conjugated molecules access to fascinating specific interactions with circularly polarized light (CPL). Such a feature enables the fabrication of high‐performance chiral organic electronic devices that detect or emit CPL directly. Herein, we show that chiral fused‐ring electron acceptor BTP‐4F single crystal‐based phototransistors demonstrate distinguished CPL discrimination capability with current dissymmetry factor (g) exceeding 1.4, one of the highest values among state‐of‐the‐art direct CPL detectors. The theoretical calculations prove that the chirality at the supramolecular level in these enantiomeric single crystals originates from chiral exciton coupling of a unique quasi‐two‐dimensional supramolecular organization consisting of interlaced molecules with opposite helical conformation. Impressively, such supramolecular organization produces a higher g along the preferred growth direction of the chiral single crystals in comparison to that of the short axis direction. Furthermore, the amplified, inverted, and also anisotropic current dissymmetry compared to optical dissymmetry has been studied by the finite element simulations. Therefore, we develop a unique chiral supramolecular organization that is responsible for the excellent chiroptical response and anisotropic electronic properties, which not only enables the construction of high‐performance CPL detection devices but also allows a better understanding of the structure‐property relationships in chiral organic optoelectronics.This article is protected by copyright. All rights reserved

Chiral Conjugated Molecular Assemblies Interact with Substances and Light

“…CD and g -factor spectra of single- and multicomponents. CD and g -factor spectra of (a) ( S , S )-, ( R , R )-BTP-4F films and self-assemblies, Reproduced with permission from ref . Copyright 2023 Wiley-VCH.…”

“…This further promotes these detectors show promising g SC / g ph with desired photodetection performance (Supporting Information Table 1). − ,,− As there have been several excellent reviews detailing the CPL detection recently, , in this section, we emphasize the relations between supramolecular chirality of active materials and the discrimination ability of CPL detectors.…”

“…In this regard, we introduced point chirality into the molecular structure of fluoride-modified fused-ring electron acceptor com-BTP-4F (Figure 5a and b). 31 Once the racemic 2-ethylhexyl group was replaced by an enantiopure (S)-/(R)-3,7-dimethyloctyl group, the supramolecular organization was greatly altered. A unique quasi-2D supramolecular packing motif formed by interlaced righthanded (P) and left-handed (M) molecules was observed in (S,S)-/(R,R)-BTP-4F crystals, rather than the 3D interpenetrating supramolecular network consisting of two pairs of helical enantiomers observed in com-BTP-4F crystals (Figure 5).…”

“…Surprisingly, a distinguished g ph of 1.4 was detected along the long axis of crystals in (S,S)-BTP-4F OFETs, while the g reduced by half along the short axis direction (Figure 13e, f). 31 It is worth noting that the sign of g is opposite with g abs . Compared with photodiodes operating at zero bias, the working mechanism of phototransistors is much more complicated, as both optical and electrical fields are involved in photodetection.…”

“…In addition to the fresh fused-ring molecular structure, their outstanding electrical and optoelectronic properties can be significantly attributed to the intermolecular packing. In this regard, we introduced point chirality into the molecular structure of fluoride-modified fused-ring electron acceptor com -BTP-4F (Figure a and b) . Once the racemic 2-ethylhexyl group was replaced by an enantiopure ( S )-/( R )-3,7-dimethyloctyl group, the supramolecular organization was greatly altered.…”