Enhanced thermoelectric properties of Sb2Te3 and Bi2Te3 films for flexible thermal sensors

Eliana M. F. Vieira, Joana Figueira, Ana Lúcia Pires, José Grilo, Manuel F. Silva, André M. Pereira, Luis Miguel Gonçalves

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Improved thermoelectric properties of p-Sb2Te3 and n-Bi2Te3 films deposited by thermal co-evaporation at 503 K and 543 K, respectively, are reported, by using two types of substrate (borosilicate glass and 25 μm - Kapton® polyimide). Seebeck coefficients of 194 μV K−1 and - 233 μV K−1 and electrical conductivities of 3.2 × 104 (Ω m)−1 and 5.0 × 104 (Ω m)−1, lead to optimized power factors of 1.2 × 10−3 W K−2 m−1 and 2.7 × 10−3 W K−2 m−1, measured at 298 K, for flexible Sb2Te3 and Bi2Te3 films, respectively. The power factor value increases until a maximum of 2.3 × 10−3 W m−1 K−2 for the p-type film, and to 5.9 × 10−3 W m−1 K−2 for the n-type film, at 373 K, respectively. An improvement of more than two times on the power factor value is observed when compared with the actual state-of-art for flexible Sb2Te3 and Bi2Te3 films, at room temperature, with thickness below 1 μm. A flexible thermopile sensor based on p - n films is presented, into possible thermal sensing. The thermoelectric device shows a responsivity of 0.05 V W−1 and a specific detectivity of 1.6 × 107 cm √Hz W−1.

Original languageEnglish
Pages (from-to)1102-1116
Number of pages15
JournalJournal Of Alloys And Compounds
Volume774
DOIs
Publication statusPublished - 5 Feb 2019

Keywords

  • Antimony telluride
  • Bismuth telluride
  • Flexible thermal sensor
  • Kapton substrate
  • Thermoelectric effect

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