Band alignment of monolayer CaP$_3$, CaAs$_3$, BaAs$_3$ and the role of $p$-$d$ orbital interactions in the formation of conduction band minima
| Autor: | Magdalena Laurien, Oleg Rubel, Himanshu Saini |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Band gap Anderson's rule Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences General Physics and Astronomy Heterojunction 02 engineering and technology Electronic structure 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics 3. Good health 0104 chemical sciences Phosphorene chemistry.chemical_compound chemistry Monolayer Quasiparticle Direct and indirect band gaps Physical and Theoretical Chemistry 0210 nano-technology |
| Popis: | Recently, a number of new two-dimensional (2D) materials based on puckered phosphorene and arsenene have been predicted with moderate band gaps, good absorption properties and carrier mobilities superior to transition metal dichalcogenides. For heterojunction applications, it is important to know the relative band alignment of these new 2D materials. We report the band alignment of puckered CaP$_3$, CaAs$_3$ and BaAs$_3$ monolayers at the quasiparticle level of theory (G$_0$W$_0$), calculating band offsets for isolated monolayers according to the electron affinity rule. Our calculations suggest that monolayer CaP$_3$, CaAs$_3$ and BaAs$_3$ all form type-II (staggered) heterojunctions. Their quasiparticle gaps are 2.1 (direct), 1.8 (direct) and 1.5 eV (indirect), respectively. We also examine trends in the electronic structure in the light of chemical bonding analysis. We show that the indirect band gap in monolayer BaAs$_3$ is caused by relatively strong As $3p$ - Ba $5d$ bonding interactions that stabilize the conduction band away from the $\Gamma$ point between $\Gamma$ and $S$. Comment: 23 pages, 4 figures |
| Databáze: | OpenAIRE |
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