Insights into Structural, Electronic, and Transport Properties of Pentagonal PdSe2 Nanotubes Using First-Principles Calculations

Abstract

One-dimensional (1D) novel pentagonal materials have gained significant attention as a new class of materials with unique properties that could influence future technologies. In this report, we studied the structural, electronic, and transport properties of 1D pentagonal PdSe2 nanotubes (p-PdSe2 NTs). The stability and electronic properties of p-PdSe2 NTs with different tube sizes and under uniaxial strain were investigated using density functional theory (DFT). The studied structures showed an indirect-to-direct bandgap transition with slight variation in the bandgap as the tube diameter increased. Specifically, (5 × 5) p-PdSe2 NT, (6 × 6) p-PdSe2 NT, (7 × 7) p-PdSe2 NT, and (8 × 8) p-PdSe2 NT are indirect bandgap semiconductors, while (9 × 9) p-PdSe2 NT exhibits a direct bandgap. In addition, under low uniaxial strain, the surveyed structures were stable and maintained the pentagonal ring structure. The structures were fragmented under tensile strain of 24%, and compression of −18% for sample (5 × 5) and −20% for sample (9 × 9). The electronic band structure and bandgap were strongly affected by uniaxial strain. The evolution of the bandgap vs. the strain was linear. The bandgap of p-PdSe2 NT experienced an indirect–direct–indirect or a direct–indirect–direct transition when axial strain was applied. A deformability effect in the current modulation was observed when the bias voltage ranged from about 1.4 to 2.0 V or from −1.2 to −2.0 V. Calculation of the field effect I–V characteristic showed that the on/off ratio was large with bias potentials from 1.5 to 2.0 V. This ratio increased when the inside of the nanotube contained a dielectric. The results of this investigation provide a better understanding of p-PdSe2 NTs, and open up potential applications in next-generation electronic devices and electromechanical sensors.

Adsorption effects of acetone and acetonitrile on defected penta-PdSe2 nanoribbons: a DFT study

“…To evaluate the thermal stability in all studied cases, the formation energy [ E C (eV)] of the pristine ZZ7 p-PdSe 2 NR and its vacancy samples are calculated. The E C is calculated based on the following formula 14 …”

“…With ribbon structures, vacancies can form at the edges or inside the structure. Unlike penta graphene nanoribbon, the SS edge structure is considered to be the most stable, 14 the ZZ edge structure of penta palladium diselenide nanoribbon displays the most stable energy. 40 However, edge-defected ZZ p-PdSe 2 NRs are unstable.…”

“…[11][12][13] One of the ways to tune the electronic properties of 2D materials is to create nanostructures, including nanoribbons, nanotubes, and quantum dots that result in edge terminations and quantum connement effects. [14][15][16][17] Specically, nanoribbons are particularly interesting, as they can exhibit different edge congurations and edge states, which can signicantly affect their electronic and magnetic properties. For example, zigzag-edged nanoribbons usually have metallic edge states, while armchair-edged nanoribbons can have either metallic or semiconducting behavior depending on their width.…”