Giant enhancement of the figure-of-merit over a broad temperature range in nano-boron incorporated Cu₂Se

Abstract

We demonstrate that insulating-boron nanoparticle inclusion in Cu2Se has little effect on the overall power factor, but can significantly reduce the thermal conductivity, resulting in great improvement on zT, by a factor of 1.6–2.6 compared to undoped Cu2Se over a wide range of temperatures.

Promising and Eco‐Friendly Cu2X‐Based Thermoelectric Materials: Progress and Applications

“…Comparing with nanoengineering, introducing secondary phases can reduce κ l of Cu 2 X‐based thermoelectric materials more effectively. Astonishingly, ultralow κ l of Cu 2 Se (<0.1 W m −1 K −1 ) has been reported leading to zT values of >2 from 873 to 1000 K, such as CNT and CuInSe 2 . Regardless of strategies focusing on reducing l through phonon scattering, pores can not only reduce l through phonon‐scattering, but also reduce C v and v to realize further κ l reduction, leading to subsequently increased zT …”

“…Homogeneously distributed secondary phases can also significantly reduce κ l of Cu 2 X. For example, introducing SiC, CuGaSe 2 , nanoboron, carbon‐coated nanoboron, CNTs or graphene networks into Cu 2 Se matrix can effectively reduce κ l and subsequently enhance zT. Similarly, CNTs, carbon, and In 2 S 3 can also reduce κ l of Cu 2 S, as well as the Cu 1.15 In 2.29 Te 4 in Cu 2 Te .…”

“…a) Measured generalized density of states (GDOS) of Cu 2 Se under 500 K and graphite under 320 K . b) Temperature ( T )‐dependent lattice thermal conductivity (κ l ) and c) dimensionless figure of merit ( zT ) of the pristine Cu 2 Se in comparison with those containing additional carbon nanotubes (CNTs) . d) Hole concentration ( n H )‐dependent zT under different lattice thermal conductivity (κ l ) of Cu 2 Se in comparison with those containing additional CNTs under 800 K (experimental n H at 800 K is estimated from the room‐temperature n H and the temperature dependency shown in Figure a) …”

Current State‐of‐the‐Art in the Interface/Surface Modification of Thermoelectric Materials

“…Among the several types of second phases that have been incorporated into TE materials to enhance their zT value, silicon carbide nanoparticles have attracted significant interest. Many semiconductors, such as SiC, [ 131–142 ] MgB 2 , [ 143,144 ] TiN, [ 145,146 ] B, [ 147–149 ] and others, [ 150–152 ] have been confirmed to improve both the mechanical and thermoelectric performance of TE materials.…”

Thermoelectric properties and stability of Ba3Cu16 − xSe11 − yTey

“…[7][8][9] Ultimately, the reduced Cu concentration inside these materials will impact the resistivity. Adding heteroatoms such as Li, 10 B, 11 and Sn 12 to Cu 2 Se as well as adding interfaces with the ability of ion blocking between different segments of a Cu 2 Se thermoelectric leg could improve the stability of this material. 7 Here, incorporating larger elements such as Ba and Te was considered as a strategy to reduce the Cu ion migration.…”