Anomalous transport and thermoelectric performances of CuAgSe compounds

TL;DR

This study investigates the electric and thermoelectric properties of CuAgSe in its two phases, revealing potential for thermoelectric applications due to its low thermal conductivity and promising figure of merit at elevated temperatures.

Contribution

It provides a comparative analysis of the transport properties of CuAgSe's two phases, highlighting their potential for thermoelectric applications.

Findings

{eta}-CuAgSe is a p-type semiconductor with low thermal conductivity.

{ extalpha}-CuAgSe shows metallic conduction with n-type carriers.

The figure of merit zT reaches ~0.95 at 623 K for {eta}-CuAgSe.

Abstract

The copper silver selenide has two phases: the low-temperature semimetal phase ({\alpha}-CuAgSe) and high-temperature phonon-glass superionic phase (\b{eta}-CuAgSe). In this work, the electric transport and thermoelectric properties of the two phases are investigated. It is revealed that the \b{eta}-CuAgSe is a p-type semiconductor and exhibits low thermal conductivity while the {\alpha}-CuAgSe shows metallic conduction with dominant n-type carriers and low electrical resistivity. The thermoelectric figure of merit zT of the polycrystalline \b{eta}-CuAgSe at 623 K is ~0.95, suggesting that superionic CuAgSe can be a promising thermoelectric candidate in the intermediate temperature range.