Phase Stabilization of In₂Se₃ by Disordered Ni Intercalation and its Enhanced Thermoelectrical Performance

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Van der Waals (vdW) layered materials possess unique properties due to their structure.
• Intercalation of guest atoms precisely tunes material properties by exploiting weak interlayer bonding.

Purpose of the Study:

• Synthesize a ternary compound NiₓIn₂Se₃ (x = 0-0.3) via intercalation.
• Investigate the effect of Ni intercalation on the structural, electrical, and thermoelectric properties of In₂Se₃.

Main Methods:

• Electron-injection-driven intercalation route to synthesize NiₓIn₂Se₃.
• Characterization of structural stability at elevated temperatures.
• Measurement of in-plane and out-of-plane electrical and thermal conductivity.
• Calculation of thermoelectric figure of merit (ZT).

Main Results:

• Successfully synthesized NiₓIn₂Se₃ with Ni randomly occupying In₂Se₃ interlayers.
• Intercalated Ni atoms stabilized the In₂Se₃ structure, suppressing phase transitions.
• Disordered Ni intercalation enhanced electrical conductivity and reduced thermal conductivity.
• Thermoelectric figure of merit (ZT) increased by 86% (in-plane) and 222% (out-of-plane) for Ni₀.₃In₂Se₃ at 500°C.

Conclusions:

• Nickel intercalation is an effective strategy to enhance the thermoelectric performance of vdW layered materials like In₂Se₃.
• The study demonstrates the potential of intercalation chemistry for tuning properties and expanding applications of layered materials.