Phase-Defined van der Waals Schottky Junctions with Significantly Enhanced Thermoelectric Properties

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Van der Waals materials offer unique electronic properties.
• Thermoelectric devices convert heat to electricity, but efficiency is often limited.
• Indium selenide (In2Se3) is a promising layered material.

Purpose of the Study:

• To investigate the thermoelectric properties of van der Waals Schottky junctions in multilayer In2Se3.
• To understand the mechanism behind enhanced thermoelectric performance.
• To explore the potential of interface engineering in 2D materials for thermoelectric applications.

Main Methods:

• Fabrication of van der Waals Schottky junctions using crystalline phases of multilayer In2Se3.
• Characterization of electrical transport properties, including diode behavior and gate tunability.
• Measurement of thermoelectric power and figure-of-merit.

Main Results:

• Demonstrated ideal diode behavior and gate-tunable current rectification in the In2Se3 junctions.
• Achieved a significant enhancement in thermoelectric power (over three orders of magnitude) compared to single-phase In2Se3.
• Thermoelectric figure-of-merit approached ~1 at room temperature.
• Attributed the enhancement to Schottky barrier-induced hot carrier transport, not 2D quantum confinement.

Conclusions:

• Van der Waals Schottky junctions in multilayer In2Se3 exhibit significantly enhanced thermoelectric properties.
• The observed effects are attributed to interface engineering (Schottky barrier) rather than solely quantum confinement.
• This approach demonstrates a viable strategy for improving thermoelectric performance in van der Waals materials beyond the few-layer limit.