New materials science papers: Diboron-porphyrin monolayer and BiSbTe nanofilms

In the last few weeks we had two papers published in materials science journals: “Diboron-porphyrin monolayer: A new 2D semiconductor” has been published in Computational Materials Science and “Thermoelectric properties of BiSbTe alloy nanofilms produced by DC sputtering: experiments and modeling” has been published in Journal of Materials Science.

In the first one, we investigate a new 2D material with BC10Nstoichiometry based on the molecular structure of diboron porphyrin. Ab-initio molecular dynamics simulations indicate mechanical stability up to 4000 K. Electronic structure calculations based on density functional theory predict a 0.6 eV direct band gap. Non-equilibrium molecular dynamics simulations predict anisotropic lattice thermal conductivities of 160 and 115  W/m–K along perpendicular in-plane directions at room temperature. Overall the results indicate that, in spite of its interesting anisotropic transport properties, diboron porphyrin monolayers are not suitable candidates for thermoelectric applications.

In the second one, we analyze the deposition of BiSbTe films and the effect of a thermal treatment on their thermoelectric properties. We produced sputtering targets from decommissioned commercial thermoelectric modules, exploring an environmentally responsible destination for discarded devices. Films deposited by DC sputtering presented an improvement in thermoelectric efficiency as the annealing temperature was increased from 423 K to 623 K. We modeled the effect of the annealing temperature on thermal conductivity, electrical resistivity, and Seebeck coefficient with the theory of q-deformed algebra, and related the q-factor to structural properties of the films. This work could pave the way for modeling experimental measurements via the formalism of q-deformation algebra.

Both publications result from collaboration with colleagues at Universidade Federal do Rio Grande do Norte, Universidade Federal da Paraíba and Universidade Federal de Campina Grande.

I must be getting closer to becoming a real materials scientist now.

Posted in TNG Publications