Doping Copper Selenide for Tuning the Crystal Structure and Thermoelectric Performance of Germanium Telluride-Based Materials

Abstract

Germanium telluride (GeTe) compounds exhibit excellent thermoelectric performance. In this study, copper selenide (Cu 2 Se) was used to tune the crystal structure and carrier concentration (n H ) of GeTe materials. The zT of the 1% Cu 2 Se-doped GeTe sample reaches 1.32, which is 52% higher than that of the pure phase. The results show that Cu 2 Se tunes the GeTe crystal structure and carrier concentration to achieve promising enhancements to the thermoelectric performance. Meanwhile, a herringbone-like crystal structure that reduces the lattice thermal conductivity was observed. However, because the directional movement of Cu ions at high temperatures leads to an increase in electrical conductivity, the electronic thermal conductivity also increased. This study focuses on crystal engineering strategies for the study of nontoxic thermoelectric materials.

Achieving High Thermoelectric Performance in ZnSe-Doped CuGaTe2 by Optimizing the Carrier Concentration and Reducing Thermal Conductivity

“…4,5 Typically, thermoelectric material properties were evaluated using the dimensionless parameter ZT = S 2 σT/(κ l + κ e ), 6,7 where S represents the Seebeck coefficient, σ stands for the electrical conductivity, T is the absolute temperature, κ l is the lattice thermal conductivity, and κ e is the electronic thermal conductivity. 8,9 Achieving high ZT value necessitates elevated electrical conductivity and Seebeck coefficient, while maintaining relatively low thermal conductivity. 10−14 However, there exists a coupled relationship among S, σ, and κ e making it challenging to solely control any individual parameter.…”

“…The increasingly severe fossil fuel crisis and greenhouse effect are placing unprecedented pressure on energy supply. , Thermoelectric materials, due to their ability to mutually convert thermal energy into electrical energy, have garnered significant attention as they can efficiently convert industrial waste heat into electrical energy. , Typically, thermoelectric material properties were evaluated using the dimensionless parameter ZT = S 2 σ T /(κ l + κ e ), , where S represents the Seebeck coefficient, σ stands for the electrical conductivity, T is the absolute temperature, κ l is the lattice thermal conductivity, and κ e is the electronic thermal conductivity. , Achieving high ZT value necessitates elevated electrical conductivity and Seebeck coefficient, while maintaining relatively low thermal conductivity. − However, there exists a coupled relationship among S, σ, and κ e making it challenging to solely control any individual parameter. − Therefore, researchers have explored various methods for comprehensive control, such as adjusting carrier concentration and band engineering to improve electrical performance, − and implementing phonon engineering to reduce thermal conductivity. , …”

Aromatic and magnetic properties in a series of heavy rare earth‐doped Ge6 cluster anions

“…Germanium, serving as a traditional semiconductor material, is extensively utilized in various fields such as infrared optical systems, fiber‐optic communication systems, and solar energy cells 14–17 . Germanium‐doped materials exhibit superior properties compared to pure germanium, including enhanced electrical conductivity, improved temperature stability, superior optoelectronic performance, and reduced cost 18–23 . The performance of germanium materials can be enhanced through rare earth doping from multiple perspectives.…”