A computational study of anisotropic charge transport in air-stable fluorinated benzobisbenzothiophene (FBBBT) derivatives

Smruti Ranjan Sahoo; Sagar Sharma; Sridhar Sahu

doi:10.1007/s00894-019-4251-9

A computational study of anisotropic charge transport in air-stable fluorinated benzobisbenzothiophene (FBBBT) derivatives

J Mol Model. 2019 Dec 18;26(1):14. doi: 10.1007/s00894-019-4251-9.

Authors

Smruti Ranjan Sahoo¹, Sagar Sharma², Sridhar Sahu³

Affiliations

¹ High Performance Computing Lab, Department of Applied Physics, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India.
² Department of Chemistry, School of Fundamental and Applied Sciences, Assam Don Bosco University, Tapesia Gardens, Guwahati, Assam, 782402, India.
³ High Performance Computing Lab, Department of Applied Physics, Indian Institute of Technology (ISM), Dhanbad, Jharkhand, 826004, India. sridharsahu@iitism.ac.in.

PMID: 31853659
DOI: 10.1007/s00894-019-4251-9

Abstract

A computational study of anisotropical charge transport properties of fluorinated benzobisbenzothiohphene derivatives (FBBBT) is presented. The values of IP_adia of all FBBBTs are found in the range of 6.00-6.20 eV inferring the fact that the investigated compounds have ambient air-stability. In addition, the energy levels of FBBBT s are found to be lower than those of benzobisbenzothiophene (BBBT) compound indicating higher charge carrier stability in the former. Hirshfield surface analyses showed that, in all the studied compounds, the principal identifiable interaction were mostly due to F⋯H and H⋯H intermolecular couplings with no contribution from S⋯S bondings. The calculated maximum μ_hole(μ_elec) value of the compounds FBBBT-a and FBBBT-b was found to be 0.483 (0.794) cm²V^{- 1}s^{- 1} and 0.688 (0.542) cm²V^{- 1}s^{- 1} respectively in the direction of transistor channel (Φ = 93.39 ^∘(273.30^∘) for FBBBT-a and Φ = 92.24 ^∘/272.72 ^∘ for FBBBT-b). For FBBBT-c, the maximum μ_elec(μ_hole) value of 0.933 (0.233) cm²V^{- 1}s^{- 1} appeared for Φ = 0 ^∘/179.90 ^∘. In addition, the compounds FBBBT-a and FBBBT-b possess two additional fluorine atoms attached at the X positions in the backbone, which result in an increment in μ_elec values (1.4 times and 0.78 times higher than μ_hole) in these two compounds at a particular crystal direction.

Keywords: Anisotropic charge mobility; Density functional theory; Fluorinated benzobisbenzothiophene derivatives; Hirshfield surface.