Seminarium "Coherence-Correlations-Complexity" (KFT, PWr)
Sala 320a bud. A-1, Politechnika Wrocławska
Modelling electronic properties of atomically thin nanostructures within tight binding model and DFT methods
Ludmiła Szulakowska
Katedra Fizyki Teoretycznej Wydziału PPT Politechniki Wrocławskiej
We study electronic properties of atomically thin nanostructures within the tight-binding (TB) model and density functional theory (DFT) methods. The investigated structures include graphene quantum dots of different sizes, shapes and edge types and transition metal dichalcogenide (TMDC) MX2 (M: Mo, W and X: S, Se, Te) nanoribbons and quantum dots.
For graphene nanostructures the effect of the choice of exchange-correlation functionals on obtained electronic properties is discussed. A magnitude of the energy gap is analysed. Additionally, we study how the relaxation of the structure influences its atomic distances. We derive an accurate TB model for quantum dots with their geometry optimized in DFT and TB parameters changed accordingly. This allows us to analyse the spectra of larger nanostructures.
Our studies of TMDCs involve the application of three band TB model to investigate the electronic properties of MoS2 nanostructures. We prove its inadequacy to produce the spectra of nanoribbons and quantum dots in comparison to DFT results. This forces one to use eleven-orbital TB model.
