TTT2I3 ORGANIC CRYSTALS – A PROMISING PLATFORM FOR LOWDIMENSIONAL THERMOELECTRIC DEVICES

Abstract

In this paper, we provide an analysis of quasi-one-dimensional organic crystals of TTT₂I₃ (tetrathiotetracene-iodide) with respect to their thermoelectric properties. An advanced physical model was employed. The main Hamiltonian of the model includes the electronic and phonon contributions, electron-phonon interactions, and an impurityscattering term. To capture charge transport between molecular chains, the model was extended to a three-dimensional framework. Numerical simulations were conducted to evaluate electrical conductivity, Seebeck coefficient, thermal conductivity, thermoelectric power factor, and figure of merit as functions of carrier concentration, temperature, and impurity content. Additionally, the Peierls structural transition in the TTT chains was analyzed, allowing determination of the critical transition temperature. The dispersion of renormalized phonons was examined in the random phase approximation for different temperatures.