Important role of Cu in suppressing bipolar conduction in Bi-rich (Bi,Sb)2Te3

Kyu Hyoung Lee; Weon Ho Shin; Hyun Sik Kim; Hyun joon Cho; Sung Wng Kim; Sang il Kim

doi:10.1016/j.scriptamat.2020.05.039

Important role of Cu in suppressing bipolar conduction in Bi-rich (Bi,Sb)₂Te₃

Kyu Hyoung Lee, Weon Ho Shin, Hyun Sik Kim, Hyun joon Cho, Sung Wng Kim, Sang il Kim

Department of Materials Science and Engineering

Research output: Contribution to journal › Article › peer-review

8 Scopus citations

Abstract

Cu doping has been known to enhance thermoelectric performance of p-type (Bi,Sb)₂Te₃ alloys by suppressing bipolar conduction at higher temperatures. However, detailed mechanisms are not provided yet. Herein, we investigate the unchallenged role of Cu doping in (Bi,Sb)₂Te₃ alloys by means of Bi-rich compositions of Bi_0.6Sb_1.4Te₃ and Bi_0.7Sb_1.3Te₃, which were chosen since they exhibit much inferior thermoelectric performance owing to severe bipolar conduction. It was found that Cu doping increases non-degenerate mobility and density-of-states effective mass of valence band as well as hole concentration. Small amount of Cu doping enhanced maximum thermoelectric figure-of-merit of Bi_0.6Sb_1.4Te₃ composition from 0.25 to 0.98.

Original language	English
Pages (from-to)	225-229
Number of pages	5
Journal	Scripta Materialia
Volume	186
DOIs	https://doi.org/10.1016/j.scriptamat.2020.05.039
State	Published - Sep 2020

Keywords

Bipolar conduction
Doping
Effective mass
Thermoelectric
Weighted mobility

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10.1016/j.scriptamat.2020.05.039

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title = "Important role of Cu in suppressing bipolar conduction in Bi-rich (Bi,Sb)2Te3 ",

abstract = "Cu doping has been known to enhance thermoelectric performance of p-type (Bi,Sb)2Te3 alloys by suppressing bipolar conduction at higher temperatures. However, detailed mechanisms are not provided yet. Herein, we investigate the unchallenged role of Cu doping in (Bi,Sb)2Te3 alloys by means of Bi-rich compositions of Bi0.6Sb1.4Te3 and Bi0.7Sb1.3Te3, which were chosen since they exhibit much inferior thermoelectric performance owing to severe bipolar conduction. It was found that Cu doping increases non-degenerate mobility and density-of-states effective mass of valence band as well as hole concentration. Small amount of Cu doping enhanced maximum thermoelectric figure-of-merit of Bi0.6Sb1.4Te3 composition from 0.25 to 0.98.",

keywords = "Bipolar conduction, Doping, Effective mass, Thermoelectric, Weighted mobility",

author = "Lee, {Kyu Hyoung} and Shin, {Weon Ho} and Kim, {Hyun Sik} and Cho, {Hyun joon} and Kim, {Sung Wng} and Kim, {Sang il}",

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doi = "10.1016/j.scriptamat.2020.05.039",

language = "English",

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pages = "225--229",

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T1 - Important role of Cu in suppressing bipolar conduction in Bi-rich (Bi,Sb)2Te3

AU - Lee, Kyu Hyoung

AU - Shin, Weon Ho

AU - Kim, Hyun Sik

AU - Cho, Hyun joon

AU - Kim, Sung Wng

AU - Kim, Sang il

PY - 2020/9

Y1 - 2020/9

N2 - Cu doping has been known to enhance thermoelectric performance of p-type (Bi,Sb)2Te3 alloys by suppressing bipolar conduction at higher temperatures. However, detailed mechanisms are not provided yet. Herein, we investigate the unchallenged role of Cu doping in (Bi,Sb)2Te3 alloys by means of Bi-rich compositions of Bi0.6Sb1.4Te3 and Bi0.7Sb1.3Te3, which were chosen since they exhibit much inferior thermoelectric performance owing to severe bipolar conduction. It was found that Cu doping increases non-degenerate mobility and density-of-states effective mass of valence band as well as hole concentration. Small amount of Cu doping enhanced maximum thermoelectric figure-of-merit of Bi0.6Sb1.4Te3 composition from 0.25 to 0.98.

AB - Cu doping has been known to enhance thermoelectric performance of p-type (Bi,Sb)2Te3 alloys by suppressing bipolar conduction at higher temperatures. However, detailed mechanisms are not provided yet. Herein, we investigate the unchallenged role of Cu doping in (Bi,Sb)2Te3 alloys by means of Bi-rich compositions of Bi0.6Sb1.4Te3 and Bi0.7Sb1.3Te3, which were chosen since they exhibit much inferior thermoelectric performance owing to severe bipolar conduction. It was found that Cu doping increases non-degenerate mobility and density-of-states effective mass of valence band as well as hole concentration. Small amount of Cu doping enhanced maximum thermoelectric figure-of-merit of Bi0.6Sb1.4Te3 composition from 0.25 to 0.98.

KW - Bipolar conduction

KW - Doping

KW - Effective mass

KW - Thermoelectric

KW - Weighted mobility

UR - http://www.scopus.com/inward/record.url?scp=85085640745&partnerID=8YFLogxK

U2 - 10.1016/j.scriptamat.2020.05.039

DO - 10.1016/j.scriptamat.2020.05.039

M3 - Article

AN - SCOPUS:85085640745

SN - 1359-6462

VL - 186

SP - 225

EP - 229

JO - Scripta Materialia

JF - Scripta Materialia

ER -

Important role of Cu in suppressing bipolar conduction in Bi-rich (Bi,Sb)₂Te₃

Abstract

Keywords

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