Strain tunable pudding-mold-type band structure and thermoelectric properties of SnP monolayer
arXiv:1912.12048 · doi:10.1063/5.0003241
Abstract
Recent studies indicated the interesting metal-to-semiconductor transition when layered bulk GeP3 and SnP3 are restricted to the monolayer or bilayer, and SnP3 monolayer has been predicted to possess high carrier mobility and promising thermoelectric performance. Here, we investigate the biaxial strain effect on the electronic and thermoelectric properties of SnP3 monolayer. Our first-principles calculations combined with Boltzmann transport theory indicate that SnP3 monolayer has the pudding-mold-type valence band structure, giving rise to a large p-type Seebeck coefficient and a high p-type power factor. The compressive biaxial strain can decrease the energy gap and result in the metallicity. In contrast, the tensile biaxial strain increases the energy gap, and increases the n-type Seebeck coefficient and decreases the n-type electrical conductivity. Although the lattice thermal conductivity becomes larger at a tensile biaxial strain due to the increased maximum frequency of the acoustic phonon modes and the increased phonon group velocity, it is still low, only e.g. 3.1 W/(mK) at room temperature with the 6% tensile biaxial strain. Therefore, SnP3 monolayer is a good thermoelectric material with low lattice thermal conductivity even at the 6% tensile strain, and the tensile strain is beneficial to the increase of the n-type Seebeck coefficient.
arXiv comment16 pages, 6 figures. Submitted to J. Phys.: Condens. Matter
References in corpus (11)
- BoltzTraP. A code for calculating band-structure dependent quantities
- Strain engineered direct-indirect band gap transition and its mechanism in 2D phosphorene
- GeP3: A small indirect band gap 2D crystal with high carrier mobility and strong interlayer quantum confinement
- Phonon Transport in Single-Layer Transition Metal Dichalcogenides: a First-Principles Study
- Electronic and Thermoelectric Properties of Few-Layer Transition Metal Dichalcogenides
- "Pudding mold" band drives large thermopower in NaCoO
- A Revisit to High Thermoelectric Performance of Single-layer MoS2
- Thermoelectric properties of orthorhombic group IV-VI monolayers from the first-principles calculations
- Enhanced power factor and reduced Lorenz number in the Wiedemann--Franz law due to pudding mold type band structures
- Large Seebeck effect in the electron-doped FeAs driven by quasi one dimensional pudding-mold type band
- Lateral heterostructures and one-dimensional interfaces in 2D transition metal dichalcogenides