Effect of Transition‐Metal Cobalt Doping on the Thermoelectric Performance of In₂O₃ Ceramics

Abstract

The polycrystalline In2O3 ceramics doped with cobalt were prepared through the spark plasma sintering (SPS) process. Both thermoelectric transport properties and microstructure of the ceramics were investigated. The Co‐doped In2O3 by SPS had a remarkable effect on the transport properties. Large electrical conductivity and thermopower was observed in dilute Co‐doped sample. The maximum power factor were found in In1.98Co0.02O3 sample as 4.6 × 10−4 W·(m·K2)−1 at 1073 K with the ZT value up to 0.26.

The thermoelectric properties of In2O3 thin films deposited by direct current magnetron sputtering

“…The absolute value of Seebeck coefficient S increases with the increase in the range of the test temperature. The temperature dependence of the Seebeck coefficient of our samples roughly agrees with those of unintentionally doped In 2 O 3 bulk [6] and In 2 O 3 :Pd nanocomposite films [12], but disagrees with others [10,11], due to different range of test temperatures or different fabrication methods. Our films were sputtering deposited with a grain size of 14.20 nm as calculated and they are not granular materials [19][20][21] since films deposited by sputtering are usually dense enough and the grains inside the films are in close contact with each other.…”

“…The power factors of our samples roughly increase with the increase in the temperature, which is similar to those of undoped In 2 O 3 and Pd doped In 2 O 3 films [12] or undoped In 2 O 3 and Co doped In 2 O 3 bulk [10]. The power factors of our samples are slightly smaller than those of undoped In 2 O 3 [12] at the same temperature, possibly due to different fabrication methods.…”

“…The power factors of our samples are slightly smaller than those of undoped In 2 O 3 [12] at the same temperature, possibly due to different fabrication methods. At the same temperature, the power factors of our undoped In 2 O 3 films are smaller than tin doped In 2 O 3 films [2] and cobalt doped In 2 O 3 bulk [10], suggesting that doping In 2 O 3 with tin or cobalt can improve the power factors. Comparing Fig.4 and Fig.5, we can find that both the Seebeck coefficient S and the power factor σ 2 S possess a similar behavior with the increase in the temperature.…”

“…There is some theoretical [13] and experimental work about the thermoelectric properties of In 2 O 3 and its dopants [2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18] . There is work [5][6][7][8][9][10] about In 2 O 3 bulk and its dopant. For example, J. Lan et al studied the thermoelectric properties of In 2 O 3 codoped with Zn and Ge [5].…”

Metal oxides for thermoelectric power generation and beyond

“…Point defect hinders the atomic-scale scattering and improves the carrier concentration thereby increasing PF. Utilizing the spark plasma-sintering process, co-doped polycrystalline In 2 O 3 ceramics were fabricated by Liu et al [110]. They have achieved high electrical conductivity and Seebeck coefficient, which resulted in PF of 4.53 × 10 −4 W/mK 2 at 1070 K for In 1.96 Co 0.04 O 3 .…”