TY - JOUR
T1 - Manipulating the phonon transport towards reducing thermal conductivity via replacement of Cu by Mn in Cu2SnSe3 thermoelectric system
AU - Gurukrishna, K.
AU - Rao, Ashok
AU - Chung, Yin Chun
AU - Kuo, Yung Kang
N1 - Funding Information:
One of the authors (AR) acknowledges DST - FIST grant (SR/FIST/PS-1/2017/8) and the Council of Scientific and Industrial Research Grant (sanction no.: 03(1409)/17/E MR-II) for the financial support required for this work. The electrical and thermal transport measurements were supported by the Ministry of Science and Technology of Taiwan under Grant Nos. MOST-109-2112-M-259-007-MY3 (YKK).
Publisher Copyright:
© 2021 Elsevier Inc.
PY - 2022/3
Y1 - 2022/3
N2 - The substitution of Cu by Mn in the Cu2-xMnxSnSe3 (0 ≤ x ≤ 0.20) system is presented with an objective to optimize the thermal transport and analyse thermoelectric behaviour in the low and near room temperature regime (10–350 K). The existence of hole-like small polarons as thermally activated carriers, mediating the p-type electrical transport at high temperatures (>80 K), is experimentally validated. Temperature dependence of Seebeck coefficient and electrical transport at low temperatures reveals that the variable range hopping (VRH) mechanism is responsible for conduction for temperatures (<80 K). Mn doping resulted in the improvement of the Seebeck coefficient, attaining the highest value of 228.3 μV/K at 350 K for the x = 0.20 sample. A reduction in thermal conductivity is achieved in all the Mn-doped samples, presumably due to strong point defect scattering of high-frequency phonons. The x = 0.20 sample has the lowest thermal conductivity of 1.68 W/mK at 350 K. Even though the ZT value is observed to decrease with Mn doping, enhancement in thermoelectric quality factor is seen for the sample with x = 0.05, which is attributed to the reduction in lattice thermal conductivity.
AB - The substitution of Cu by Mn in the Cu2-xMnxSnSe3 (0 ≤ x ≤ 0.20) system is presented with an objective to optimize the thermal transport and analyse thermoelectric behaviour in the low and near room temperature regime (10–350 K). The existence of hole-like small polarons as thermally activated carriers, mediating the p-type electrical transport at high temperatures (>80 K), is experimentally validated. Temperature dependence of Seebeck coefficient and electrical transport at low temperatures reveals that the variable range hopping (VRH) mechanism is responsible for conduction for temperatures (<80 K). Mn doping resulted in the improvement of the Seebeck coefficient, attaining the highest value of 228.3 μV/K at 350 K for the x = 0.20 sample. A reduction in thermal conductivity is achieved in all the Mn-doped samples, presumably due to strong point defect scattering of high-frequency phonons. The x = 0.20 sample has the lowest thermal conductivity of 1.68 W/mK at 350 K. Even though the ZT value is observed to decrease with Mn doping, enhancement in thermoelectric quality factor is seen for the sample with x = 0.05, which is attributed to the reduction in lattice thermal conductivity.
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U2 - 10.1016/j.jssc.2021.122755
DO - 10.1016/j.jssc.2021.122755
M3 - Article
AN - SCOPUS:85119899983
SN - 0022-4596
VL - 307
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
M1 - 122755
ER -