Thermoelectric Properties of Two-Dimensional Materials

Two-dimensional materials, comprising atomically thin layers of transition-metal dichalcogenides, group-VI dichalcogenides and other van der Waals crystals, offer a distinctive balance of electrical and thermal transport that is absent in bulk counterparts. Their reduced dimensionality enhances the Seebeck coefficient via quantum confinement while simultaneously suppressing lattice thermal conductivity through increased boundary scattering and phonon engineering. Anisotropy in lattice structure and tunable band gaps enable targeted manipulation of charge carrier mobility and thermal pathways, yielding improved thermoelectric figures of merit (ZT). Techniques such as substrate engineering, strain modulation and compositional asymmetry in Janus monolayers further decouple electrical and thermal conductivities, creating negative correlations that boost performance. Advances in interfacial design and novel heterostructures have led to compact, flexible thermoelectric generators suitable for waste-heat recovery, on-chip cooling and wearable energy harvesting. The global significance of these developments lies in their potential to underpin sustainable energy solutions, address thermal management challenges in microelectronics and enable distributed power generation from low-grade heat sources.

Research from Nature Portfolio

Recent studies have demonstrated that two-dimensional tin disulfide nanosheets exhibit a counterintuitive negative correlation between electrical and thermal conductivity as thickness decreases. Such an effect raises the thermoelectric figure of merit by orders of magnitude compared with bulk crystals, owing to enhanced carrier mobility combined with suppressed phonon transport. Foundational work on monolayer molybdenum disulfide has revisited its potential ZT by employing first-principles calculations and phonon engineering to predict reductions in thermal conductivity while maintaining high electrical conductance. These investigations underscore the feasibility of optimising single-layer transition-metal dichalcogenides through precise control of phonon dispersion and electron–phonon interactions, setting benchmarks for future device architectures.

Thermoelectric Properties of Two-Dimensional Materials publication trend

The graph below shows the total number of articles in thermoelectric properties of two-dimensional materials across all publications each year (not limited to Nature Index journals).

Technical terms

Seebeck coefficient: The voltage generated per unit temperature difference across a material, indicating its ability to convert heat into electrical energy.

Thermoelectric figure of merit (ZT): A dimensionless index defined by the ratio of power factor to thermal conductivity multiplied by temperature, representing overall conversion efficiency.

Power factor: The product of the square of the Seebeck coefficient and electrical conductivity, used to gauge the electrical performance of a thermoelectric material.

Electron–phonon scattering: Interactions between charge carriers and lattice vibrations that influence both electrical resistivity and thermal transport in crystalline solids.

References

1. Single-material MoS2 thermoelectric junction enabled by substrate engineering. npj 2D Materials and Applications (2023).
2. A Revisit to High Thermoelectric Performance of Single-layer MoS2. Scientific Reports (2015).
3. High Thermoelectric Performance in Two-Dimensional Janus Monolayer Material WS‑X (X = Se and Te). ACS Applied Materials & Interfaces (2020).
4. Strain-Enhanced Thermoelectric Performance in GeS2 Monolayer. Materials (2022).