Multi-scale investigation on high mobility emissive n-type organic semiconductors based on fluorinated diphenylanthracene isomers

Abstract

N

type high mobility emissive organic semiconductor materials (HMEOSCs) are pivotal for advancing logic circuits and sensors. Nevertheless, their development faces the great challenge in achieving both high carrier mobility and strong luminescent properties, attributed to the limitations of intrinsic molecular structure and solid-state stacking. In this study, a series of fluorinated diphenylanthracene isomers (1,5-, 2,6-, and 9,10-DPA-F) were theoretically designed, with their charge transport and fluorescence properties systematically investigated via first-principles calculations. Additionally, crystal growth morphologies were modeled to establish multiscale structure-property relationships. The results show that the perfluorination of aryl substituents were demonstrated to effectively reduce LUMO energy levels, enhance electron injection capabilities, and elevate fluorescence quantum yields beyond 70 %. However, it also brings the problems of larger reorganization energy and intermolecular sliding along the long axis. Building on this foundation, molecular redesign strategies focused on 2,6-DPA-F were developed to suppress electronic reorganization energy. Moreover, we also clarified the reason by crystal morphology growth why high mobility molecules 1,5-DPA-F and 9,10-DPA-F (μ_es>1 cm²V⁻¹s⁻¹) have not yet obtained experimental measurement values. This work elucidates the influence of multi-scale factors (molecular structure-stacking-morphology) on the transport properties, and opens up new avenues and perspectives for the design of n-type HMEOSCs.