Surface Doping Effect on the Optoelectronic Properties of Tetrachloro-Substituted Chiral Perylene Diimide Supramolecular Nanowires

Abstract

In nature, chirality displays itself in diverse forms and on various hierarchical scales. Among the various types of chirality, supramolecular chirality is of particular interest due to its ability to amplify and induce chirality, which aids in understanding the fundamental principles of chirality transfer and is also suitable for chirality applications at the macroscopic scale. Herein, we report the synthesis of a novel chiral organic semiconductor 2,9-di(hexan-2-yl)anthra[2,1,9-def:6,5,10-d&apos;e&apos;f&apos;]diisoquinoline-1,3,8,10 (2H, 9H)-tetraone (ClCPDI-C6) and its selfassembly into supramolecular nanowires (NWs). The chirality of the NWs was successfully transferred via intra- and inter-molecular interactions from the chiral pendant to the perylene diimide (PDI) core after self-assembly. Upon exposing the organic NWs to phenylhydrazine dopant vapor, the average mobility of the NW transistor was increased from 0.0085 to 0.026 cm2 V-1 s-1. Additionally, phenylhydrazine molecular doping of the NWs significantly enhanced their optical performance in comparison with the undoped NWs, with improved photoresponsivity (R) (similar to 3 times higher), photosensitivity (P) (similar to 10 times higher), external quantum efficiency (similar to 3 times higher), and detectivity (D*) (similar to 8 times higher). The detectivity of the phenylhydrazine-doped NWs was 1 or 2 orders of magnitude higher than that previously reported for chiral PDI NWs. Notably, they showed a fast and stable real-time photoswitching of both undoped and doped ClCPDI-C6 NWs (<90 ms), indicating a high sensitivity to visible light and great potential in photodetector and photoswitching applications. From density functional theory calculations, after absorbing phenylhydrazine on the ClCPDI-C6 NWs, the increased electron affinity contributes to increased optoelectronic performance. Our investigation paves the way for future in-depth studies on the relationship between the structure and supramolecular chirality with optoelectronic device performance.