Effects of Hydrostatic Pressure on Charge-Transport Properties of Anthracene-Based Derivatives with Different Stacking Patterns: A Theoretical Study

Abstract

High mobility has always been an important metric in the study of organic semiconductor materials (OSCs). Various external factors, including pressure, temperature, and light, have the potential to influence the mobility of OSCs. Pressure, in particular, can modify the intermolecular distance and molecular orbital, making it an ideal candidate for controlling carrier mobility and optimizing semiconductor device performance. However, the effect of pressure on the photoelectric behavior of organic molecules with different stacking patterns remains uncertain. To address this, we prepared a series of anthracene-based semiconductor molecules to predict the effect of hydrostatic pressure on the charge-transport properties through first-principles and multiscale computational simulations based on hopping and band transport mechanisms. Our findings indicate that the mobility of TIPSAntNa in one-dimensional (1D) π-stacking is not consistently monotonic but rather reaches a peak at 5 GPa, which is attributed to the gradual increase in pressure-induced reorganization energy (λ) and the periodic variation in transfer integral (V). Differently, for herringbone stacked crystals, the Vs increase with higher pressure, resulting in higher mobility under such conditions. This means that 1D π-stacked organic molecules exhibit enhanced sensitivity to pressure, resulting in higher mobility at low pressures. Additionally, it is noteworthy that the appropriate pressure control can convert a p-type transport material into an n-type transport material. Consequently, our research provides valuable insights for achieving enhanced performance of OSCs by modulating pressure.