Chem. J. Chinese Universities ›› 2023, Vol. 44 ›› Issue (12): 20230372.doi: 10.7503/cjcu20230372

• Physical Chemistry • Previous Articles     Next Articles

Theoretical Study of the Charge Transport Properties of Naphthalene Tetracarboxylic Diimide Organic Semiconductors Based on Different π-Core Extensions

PAN Jiazheng1, SUN Xiaoqi1, REN Aimin2, GUO Jingfu1()   

  1. 1.School of Physics,Northeast Normal University,Changchun 130024,China
    2.Institute of Theoretical Chemistry,College of Chemistry,Jilin University,Changchun 130021,China
  • Received:2023-08-17 Online:2023-12-10 Published:2023-10-08
  • Contact: GUO Jingfu E-mail:guojf217@nenu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21473071)

Abstract:

n Type organic semiconductor materials(OSCs) are essential in logic complementary circuits, but their related development has lagged behind relatively due to their poor air stability and low mobility. In this work, the charge transport properties of several typical n type OSCs naphthalene tetracarboxylic diimide(NDI) based on different π-core extensions were analyzed by first principles simulation to elucidate the charge transport properties in term of the single-molecule structural features, intermolecular stacking modes, and intermolecular interactions, respectively. The results show that all of the studied molecules also have good air stability and exhibit electron transport properties. Among them, A2 with a long axis π extension has a high electron affinity(EA) and the best air stability. Secondly, compared to NDI molecule, the reorganization energies of the NDI organic semiconductors with the long-axis/short-axis π-extension were all reduced, but the origin for their decreased reorganization energy were found to be distinctly different according to the normal modes analysis. Compared to the A1 molecule, the vibrations of the A2 with the short axis π extension was effectively suppressed in the high-frequency region, whereas the vibrations of the A3 and A4 molecules extended along the long axis were suppressed in both the high and low-frequency regions, resulting in a reduction of the reorganization energy. Finally, the nearest-neighbour dimer stacking of studied molecular crystals was analyzed, and it was found that A3 and A4 have small short-axis sliping and behave as 2D electron transport materials, with 2D average electron mobility of ca. 0.06 and 0.15 cm2·V‒1·s‒1, respectively; while A2 has larger short-axis slip and thus behaves as 1D transport materials, with their 1D electron mobility as high as 0.96 cm2·V‒1·s‒1. In this paper, the relationship between molecular structure-molecular stacking patterns-electron transport properties of several typical n type OSCs NDI with different core structures was analyzed through theoretical computational simulations, which provides useful design ideas for the design of stable high-performance electron transport materials.

Key words: Organic semiconductor, Charge transport property, Electron mobility, Molecular stacking pattern, Intermolecular interaction

CLC Number: 

TrendMD: