Hybridization of n-type Bi2Te3 crystals with liquid-like copper chalcogenide elicits record-high thermoelectric performance
Journal
Materials Today Physics
Journal Volume
34
Start Page
101065
ISSN
25425293
Date Issued
2023
Author(s)
Abstract
The modern era of thermoelectricity (TE) is born alongside the explosion of nanotechnology. Although high-dose doping rejuvenates TE research, expectations for low thermal conductivity κ and high electrical transport property remain conflicting. The n-type Bi2Te3 with dilute liquid-like copper chalcogenide realizes the hybridization of electronic and ionic conduction and fulfills the concept of phonon-liquid electron-crystal. The presence of Cu2S nano-clusters modulates the concentration of Cu and Cu ion dynamically. Under such circumstances, the solubility of Cu in n-type Bi2Te3 retains at a maximal level without forming undesired impurity phases. Moreover, the Cu ions play a double role as phonon scatters and high-mobility carriers, yielding the reduced κL with enhanced carrier mobility μH. Meanwhile, a high electrical conductivity σ is retained by pinning the carrier concentration nH in the optimal level of 1019 cm−3 with the incorporation of electron donors. Consequently, our nearly single-phase n-type Bi2Se0.02Te3Cu0.03(Cu2S)0.0125 crystal achieves a large S2σ, a record-breaking zT = 1.6 at 363 K, and an ultrahigh average zT = 1.38 in the temperature range of 300 K–500 K. © 2023 Elsevier Ltd
Subjects
Copper chalcogenides
Ionic conduction
n-type Bi2 Te3
Phonon-liquid electron-crystal
Thermoelectric figure-of-merit
Publisher
Elsevier Ltd
Description
論文編號: 101065
Type
journal article