TITLE:
Investigating the Potential of Quasi-One-Dimensional Organic Crystals of TTT(TCNQ)2 for Thermoelectric Applications
AUTHORS:
Silvia Andronic, Ionel Sanduleac
KEYWORDS:
Organic Materials, Tetrathiotetracene-Tetracyanoquinodimethane, Thermoelectric Figure of Merit, Renormalized Phonon Spectrum, Peierls Tran-sition
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.14 No.1,
January
26,
2024
ABSTRACT: The purpose of this paper is to present the results of investigations on
quasi-one-dimensional organic crystals of
tetrathiotetracene-tetracyanoquinodi- methane
(TTT(TCNQ)2) from the prospective of thermoelectric applications. The calculations were performed after analytical
expressions, obtained in the frame of a physical model, more detailed than the
model presented earlier by authors. The main Hamiltonian of the model includes
the electronic and phonon part, electron-phonon interactions and the impurity
scattering term. In order to estimate the electric charge transport between the
molecular chains, the physical model was upgraded to the so-called
three-dimen- sional (3D) physical model. Numeric computations were performed to determine the electrical conductivity,
Seebeck coefficient, thermal conductivity, thermoelectric power factor
and thermoelectric figure-of-merit as a function on charge carrier
concentrations, temperatures and impurity
concentrations. A detailed analysis of charge-lattice interaction, consisting
of the exploration of the Peierls structural transition in TCNQ molecular
chains of TTT(TCNQ)2 was performed. As result, the critical
transition temperature was determined. The dispersion of renormalized phonons
was examined in detail.