TY - JOUR

T1 - All-Oxide Thermoelectric Module with in Situ Formed Non-Rectifying Complex p-p-n Junction and Transverse Thermoelectric Effect

AU - Kanas, Nikola

AU - Bittner, Michael

AU - Desissa, Temesgen Debelo

AU - Singh, Sathya Prakash

AU - Norby, Truls

AU - Feldhoff, Armin

AU - Grande, Tor

AU - Wiik, Kjell

AU - Einarsrud, Mari Ann

N1 - Funding Information: The financial support from The Research Council of Norway under the program Nano2021 to the project (number 228854) “TE materials: Nanostructuring for improving the energy efficiency of TEG and heat-pumps” (THELMA) conducted by NTNU, UiO, SINTEF, FFI, UiS, and UiA is gratefully acknowledged. We also thank for the financial support from the Deutsche Forschungsgesellschaft (DFG, German Research Foundation)-FE928/17-1. Dr Mohsin Saleemi and Dr Julian Tolchard are acknowledged for fruitful discussions.

PY - 2018/8/31

Y1 - 2018/8/31

N2 - All-oxide thermoelectric modules for energy harvesting are attractive because of high-temperature stability, low cost, and the potential to use nonscarce and nontoxic elements. Thermoelectric modules are mostly fabricated in the conventional π-design, associated with the challenge of unstable metallic interconnects at high temperature. Here, we report on a novel approach for fabrication of a thermoelectric module with an in situ formed p-p-n junction made of state-of-the-art oxides Ca3Co4-xO9+δ (p-type) and CaMnO3-CaMn2O4 composite (n-type). The module was fabricated by spark plasma co-sintering of p- and n-type powders partly separated by insulating LaAlO3. Where the n- and p-type materials originally were in contact, a layer of p-type Ca3CoMnO6 was formed in situ. The hence formed p-p-n junction exhibited Ohmic behavior and a transverse thermoelectric effect, boosting the open-circuit voltage of the module. The performance of the module was characterized at 700-900 °C, with the highest power output of 5.7 mW (around 23 mW/cm2) at 900 °C and a temperature difference of 160 K. The thermoelectric properties of the p- and n-type materials were measured in the temperature range 100-900 °C, where the highest zT of 0.39 and 0.05 were obtained at 700 and 800 °C, respectively, for Ca3Co4-xO9+δ and the CaMnO3-CaMn2O4 composite.

AB - All-oxide thermoelectric modules for energy harvesting are attractive because of high-temperature stability, low cost, and the potential to use nonscarce and nontoxic elements. Thermoelectric modules are mostly fabricated in the conventional π-design, associated with the challenge of unstable metallic interconnects at high temperature. Here, we report on a novel approach for fabrication of a thermoelectric module with an in situ formed p-p-n junction made of state-of-the-art oxides Ca3Co4-xO9+δ (p-type) and CaMnO3-CaMn2O4 composite (n-type). The module was fabricated by spark plasma co-sintering of p- and n-type powders partly separated by insulating LaAlO3. Where the n- and p-type materials originally were in contact, a layer of p-type Ca3CoMnO6 was formed in situ. The hence formed p-p-n junction exhibited Ohmic behavior and a transverse thermoelectric effect, boosting the open-circuit voltage of the module. The performance of the module was characterized at 700-900 °C, with the highest power output of 5.7 mW (around 23 mW/cm2) at 900 °C and a temperature difference of 160 K. The thermoelectric properties of the p- and n-type materials were measured in the temperature range 100-900 °C, where the highest zT of 0.39 and 0.05 were obtained at 700 and 800 °C, respectively, for Ca3Co4-xO9+δ and the CaMnO3-CaMn2O4 composite.

UR - http://www.scopus.com/inward/record.url?scp=85052554038&partnerID=8YFLogxK

U2 - 10.1021/acsomega.8b01357

DO - 10.1021/acsomega.8b01357

M3 - Article

AN - SCOPUS:85052554038

VL - 3

SP - 9899

EP - 9906

JO - ACS Omega

JF - ACS Omega

IS - 8

ER -