Enhanced high-temperature thermoelectric performance in 1D AlN nanotubes: a comparative dimensionality analysis

We report a comparative investigation of the structural, vibrational, and thermoelectric properties of aluminum nitride (AlN) across different dimensions (3D, 2D, and 1D) using density functional theory (DFT). While 3D AlN is a well-known wide-bandgap insulator, reducing the dimensionality to 1D nanotubes triggers that a (14,0) significant transition in electronic and transport behavior. Our results demonstrate that (14,0) nanotube exhibits exceptional thermoelectric efficiency at elevated temperatures (1300-1900 K). The 1D nanotubes, for example, have a power factor of 23Wm^-1 K^-2 at 1900 K, which is much better than the 2D monolayer. These results indicate that low-dimensional AlN structures are promising options for specialized energy harvesting in very hot places.

The electronic, dynamical, and thermoelectric properties of low-dimensional aluminum nitride AlN were investigated using the CRYSTAL23 code within the framework of density functional theory (DFT) employing the B3LYP hybrid exchange and correlation functional. The crystalline wave functions are expanded using atom-centered basis sets expressed as a linear combination of Gaussian-type atomic orbitals (LCAO). Raman and infrared (IR) intensities were performed by means of a coupled perturbed Kohn-Sham and Hartree-Fock (CPKS/HF) analytical approach. The electron transport properties for the 2D square slab model and 1D (14,0) nanotubes are analyzed based on the Boltzmann semi-classical theory.