TY - JOUR
T1 - Crystal Structure and Atomic Vacancy Optimized Thermoelectric Properties in Gadolinium Selenides
AU - Qin, Feiyu
AU - Nikolaev, Sergey A.
AU - Suwardi, Ady
AU - Wood, Maxwell
AU - Zhu, Yingcai
AU - Tan, Xianyi
AU - Aydemir, Umut
AU - Ren, Yang
AU - Yan, Qingyu
AU - Hu, Lei
AU - Snyder, G. Jeffrey
N1 - Funding Information:
M.W. and G.J.S. acknowledge the support of the NASA Science Missions Directorate’s Radioisotope Power Systems Technology Advancement Program. This work was also supported by Japan Society for the Promotion of Science (JSPS) KAKENHI, Grant JP 19F19057. L.H. acknowledges the International Research Fellowship of JSPS. F.Q. acknowledges the Chinese Scholarship Council (CSC) for the scholarship at Tokyo Institute of Technology. Q.Y. acknowledges Singapore MOE Tier 2 under Grant MOE2018-T2-1-010, Singapore A*STAR Pharos Program SERC 1527200022 and IAF-PP (AME domain) A19D9a0096. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Science, under Contract DE-AC02-06CH11357.
PY - 2020/12/8
Y1 - 2020/12/8
N2 - Thermoelectric materials enable the energy conversion of waste heat into electricity, helpful to relieve global energy crisis. Here, we report a systematic investigation on high-temperature thermoelectric gadolinium selenides, cubic Gd3-xSe4 (x = 0.16, 0.21, and 0.25) and orthorhombic Gd2Se3-y (y = 0.02, 0.06, and 0.08). High energy synchrotron X-ray diffraction and total scattering have been used to investigate the crystallographic and local structures. Atomic-scale clusters of Gd vacancy in the cubic phase are observed by employing the reverse Monte Carlo simulation. For cubic Gd3-xSe4, adjusting Gd vacancy triggers the effect of multiple conduction bands, confirmed by the increase in effective masses. A reasonable peak zT of 0.27 is achieved at 850 K for Gd3-xSe4 (x = 0.16). On the other hand, tuning Se vacancy enables the optimization of electron concentration for the orthorhombic Gd2Se3-y. More significantly, its low deformation potential (Z = 12 eV) gives rise to enhanced electron mobility and a higher peak zT of 0.54 at 850 K for Gd2Se3-y (y = 0.02). Intriguingly, a higher zT of 1.2 at 1200 K is reasonably predicted by quality factor analysis. This work extends the scope of high-temperature thermoelectric materials and facilitates the exploration of novel high-temperature thermoelectric materials.
AB - Thermoelectric materials enable the energy conversion of waste heat into electricity, helpful to relieve global energy crisis. Here, we report a systematic investigation on high-temperature thermoelectric gadolinium selenides, cubic Gd3-xSe4 (x = 0.16, 0.21, and 0.25) and orthorhombic Gd2Se3-y (y = 0.02, 0.06, and 0.08). High energy synchrotron X-ray diffraction and total scattering have been used to investigate the crystallographic and local structures. Atomic-scale clusters of Gd vacancy in the cubic phase are observed by employing the reverse Monte Carlo simulation. For cubic Gd3-xSe4, adjusting Gd vacancy triggers the effect of multiple conduction bands, confirmed by the increase in effective masses. A reasonable peak zT of 0.27 is achieved at 850 K for Gd3-xSe4 (x = 0.16). On the other hand, tuning Se vacancy enables the optimization of electron concentration for the orthorhombic Gd2Se3-y. More significantly, its low deformation potential (Z = 12 eV) gives rise to enhanced electron mobility and a higher peak zT of 0.54 at 850 K for Gd2Se3-y (y = 0.02). Intriguingly, a higher zT of 1.2 at 1200 K is reasonably predicted by quality factor analysis. This work extends the scope of high-temperature thermoelectric materials and facilitates the exploration of novel high-temperature thermoelectric materials.
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U2 - 10.1021/acs.chemmater.0c03581
DO - 10.1021/acs.chemmater.0c03581
M3 - Article
AN - SCOPUS:85097829216
VL - 32
SP - 10130
EP - 10139
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 23
ER -