Photothermoelectric Detection in Two-Dimensional Materials

The photothermoelectric effect harnesses temperature gradients induced by light absorption in a material to generate an electrical signal without external bias. In atomically thin semiconductors and semimetals, such as graphene, black phosphorus and transition metal dichalcogenides, the strong light–matter interaction and reduced dimensionality enhance both thermal confinement and carrier mobility. Photothermal heating creates local “hot spots” and sharp temperature differentials across device contacts, which drive charge separation via the Seebeck effect. Coupling these phenomena with van der Waals assembly, asymmetric device architectures or plasmonic nanostructures has led to detectors that operate across a broad spectrum, from ultraviolet to terahertz, with high sensitivity and rapid response times at room temperature. Recent advances have focused on overcoming traditional trade-offs between responsivity and speed by integrating photogating mechanisms, optimising heterointerfaces and engineering thermal pathways. These developments promise self-powered, chip-scale sensors for applications in environmental monitoring, medical diagnostics, security imaging and high-speed optical communications. By exploiting the versatile physics of two-dimensional materials, researchers are realising detectors that combine ultra-broadband operation, polarisation sensitivity and energy-efficient performance in a compact form factor.

Research from Nature Portfolio

Recent studies have demonstrated the enhancement of photothermoelectric conversion through the design of two-dimensional heterostructures and hybrid films. A WSe2/Ta2NiSe5 bilayer has been shown to exploit photogating-assisted tunnelling, achieving simultaneous increases in photodetection gain and response speed while offering polarisation discrimination and wavelength selectivity with a simple two-electrode planar geometry. Separately, a heterojunction formed by a silver nanostructure film and carbon nanotube layer exhibited ultra-wideband photothermal and photoelectric conversion. Localised surface plasmons in the silver film amplify light absorption in the nanotube layer, producing large temperature differentials and photovoltage responsivities across ultraviolet to terahertz wavelengths. Earlier foundational work on reduced SrTiO3 has revealed intrinsic phonon-enhanced photothermoelectric responses across a range from the visible into the long-wave infrared, underscoring the potential of unconventional oxide materials with high Seebeck coefficients for ultra-broadband self-powered detection.

Photothermoelectric Detection in Two-Dimensional Materials publication trend

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

Technical terms

Photothermoelectric effect: Generation of electrical voltage from light-induced temperature gradients via the Seebeck effect.

Seebeck coefficient: Measure of the induced voltage per unit temperature difference across a material.

Two-dimensional material: A crystalline solid consisting of a single or few atomic layers with unique electronic and thermal properties.

Heterostructure: Stacked or juxtaposed layers of different materials held together by van der Waals forces, enabling novel interfaces.

Photovoltage responsivity: Ratio of generated photovoltage to incident optical power, indicating detector sensitivity.

References

1. Photogating-assisted tunneling boosts the responsivity and speed of heterogeneous WSe2/Ta2NiSe5 photodetectors. Nature Communications (2024).
2. Local large temperature difference and ultra-wideband photothermoelectric response of the silver nanostructure film/carbon nanotube film heterostructure. Nature Communications (2022).
3. Phonon-enhanced photothermoelectric effect in SrTiO3 ultra-broadband photodetector. Nature Communications (2019).
4. Enhanced photothermoelectric conversion in self-rolled tellurium photodetector with geometry-induced energy localization. Light: Science & Applications (2024).
5. Wafer‐scale patterned growth of type‐II Dirac semimetal platinum ditelluride for sensitive room‐temperature terahertz photodetection. InfoMat (2023).
6. Hybrid Dirac semimetal-based photodetector with efficient low-energy photon harvesting. Light: Science & Applications (2022).