About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Alloys and Compounds for Thermoelectric and Solar Cell Applications XII
|
Presentation Title |
N-type Bi2Te3 Crystals with Ultrahigh Thermoelectric Performance Near Room Temperature |
Author(s) |
Hsin-Jay Wu |
On-Site Speaker (Planned) |
Hsin-Jay Wu |
Abstract Scope |
We intentionally introduced Bi-metal bilayers and small amounts of Cu into the Bi2Te3 structure by growing crystals with an off-stoichiometric chemical composition. Density functional theory (DFT) calculations suggest that the excess Bi in Bi2Te3 forms Bi-metal bilayers within the Van der Waals gaps, which covalently bond the adjacent quintuple layers. The presence of dilute copper dopants results in the generation of highly mobile copper ions and copper atoms, facilitating n-type conduction in addition to the n-type Bi-metal bilayer. The existence of both adaptive Bi bilayers and dilute Cu dopants leads to the realization of a record-breaking figure-of-merit zT near room temperature region, accompanied by an exceptionally high conversion efficiency exceeding 5% under a temperature difference (∆T) of 150 K when measured parallel to the crystal growth direction. These breakthroughs achieved by incorporating adaptive metal bilayers highlight the significant potential of anisotropic semiconductors as highly efficient electricity generators. |
Proceedings Inclusion? |
Planned: |