Impact of heat treatment temperature on the thermoelectric properties of cold-sintered SnSe

doi:10.19799/j.cnki.2095-4239.2024.0501

Abstract

Abstract:

SnSe thermoelectric materials are promising due to their low thermal conductivity, low cost, and environmental friendliness, making them a focus in thermoelectric research. This study explores the effects of heat treatment temperature on the thermoelectric properties of polycrystalline SnSe blocks prepared via hydrothermal synthesis and cold sintering. X-ray diffraction (XRD) analysis confirmed that the primary diffraction peaks of all samples corresponded with SnSe, while scanning electron microscopy (SEM) revealed a transformation from bulk to lamellar structures with reduced internal voids as annealing temperature increased. Positron annihilation spectroscopy indicated the presence of vacancy-type defects, such as V_Se, V_Sn, V_SnSe, and large vacancy clusters, which serve as phonon scattering centers, thereby reducing lattice thermal conductivity. As the annealing temperature rose, a decrease in voids and partial restoration of these defects lowered the potential barrier at grain boundaries, enhancing electrical conductivity. The electrical conductivity, power factor, and dimensionless thermoelectric figure of merit (ZT) increased consistently with higher annealing temperatures. At a test temperature of 773 K, the sample annealed at 500 ℃ exhibited an electrical conductivity (σ) of 4.1 × 10³ S/m and a power factor of 3.71 μW/(cm·K²). Although thermal conductivity slightly increased with higher annealing temperatures due to reduced phonon scattering centers, the overall ZT value reached 0.7 for the 500 ℃ annealed sample, a 35.7% improvement compared to the unannealed sample. These findings demonstrate that the combination of cold sintering and heat treatment is highly effective for enhancing the thermoelectric performance of SnSe, providing a theoretical basis for the development of high-performance thermoelectric materials.

Key words: SnSe, cold sintering, heat treatment, power factor, thermoelectric merit value, positron annihilation

CLC Number:

TB 34

Jun DING, Lijie SHI, Xiangbin CHEN, Xiang QU, Zhe CHENG, Xiufen LI, Man JIANG, Zhiquan CHEN, Hongyu WANG. Impact of heat treatment temperature on the thermoelectric properties of cold-sintered SnSe[J]. Energy Storage Science and Technology, 2024, 13(11): 3754-3763.

Figures/Tables 8

Fig.1

Fig.2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

References 37

1	ZHENG X F, LIU C X, YAN Y Y, et al. A review of thermoelectrics research-Recent developments and potentials for sustainable and renewable energy applications[J]. Renewable and Sustainable Energy Reviews, 2014, 32: 486-503. DOI: 10.1016/j.rser. 2013. 12.053.
2	FITRIANI, OVIK R, LONG B D, et al. A review on nanostructures of high-temperature thermoelectric materials for waste heat recovery[J]. Renewable and Sustainable Energy Reviews, 2016, 64: 635-659. DOI: 10.1016/j.rser.2016.06.035.
3	SHU G Q, LIANG Y C, WEI H Q, et al. A review of waste heat recovery on two-stroke IC engine aboard ships[J]. Renewable and Sustainable Energy Reviews, 2013, 19: 385-401. DOI: 10. 1016/j.rser.2012.11.034.
4	陈海生, 李泓, 徐玉杰, 等. 2023年中国储能技术研究进展[J]. 储能科学与技术, 2024, 13(5): 1359-1397. DOI: 10.19799/j.cnki.2095-4239.2024.0441.
	CHEN H S, LI H, XU Y J, et al. Research progress on energy storage technologies of China in 2023[J]. Energy Storage Science and Technology, 2024, 13(5): 1359-1397. DOI: 10.19799/j.cnki.2095-4239.2024.0441.
5	KIM T, LEE H, CHUNG I. SnSe: The rise of the ultrahigh thermoelectric performance material[J]. Bulletin of the Korean Chemical Society, 2024, 45(3): 186-199. DOI: 10.1002/bkcs. 12821.
6	ZHOU G, WANG D. High thermoelectric performance from optimization of hole-doped CuInTe₂[J]. Physical Chemistry Chemical Physics, 2016, 18(8): 5925-5931. DOI: 10.1039/c5cp 05129k.
7	CHANG C, WU M H, HE D S, et al. 3D charge and 2D phonon transports leading to high out-of-plane ZT in n-type SnSe crystals[J]. Science, 2018, 360(6390): 778-783. DOI: 10.1126/science.aaq1479.
8	DUONG A T, NGUYEN V Q, DUVJIR G, et al. Achieving ZT=2.2 with bi-doped n-type SnSe single crystals[J]. Nature Communications, 2016, 7: 13713. DOI: 10.1038/ncomms13713.
9	WANG S, HUI S, PENG K L, et al. Low temperature thermoelectric properties of p-type doped single-crystalline SnSe[J]. 2018, 112(14): 142102. DOI: 10.1063/1.5023125.
10	ZHAO L D, LO S H, ZHANG Y S, et al. Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals[J]. Nature, 2014, 508(7496): 373-377. DOI: 10.1038/nature13184.
11	TRITT T M. Holey and unholey semiconductors[J]. Science, 1999, 283(5403): 804-805. DOI: 10.1126/science.283.5403.804.
12	LIU B, HU J Z, ZHOU J, et al. Thermoelectric transport in nanocomposites[J]. Materials, 2017, 10(4): 418. DOI: 10.3390/ma10040418.
13	TAN G J, ZHAO L D, KANATZIDIS M G. Rationally designing high-performance bulk thermoelectric materials[J]. Chemical Reviews, 2016, 116(19): 12123-12149. DOI: 10.1021/acs.chemrev.6b00255.
14	YANG X, WANG Z Y, WANG J, et al. Synthesis of SnSe_1– xSx polycrystals with enhanced thermoelectric properties via hydrothermal methods combined with spark plasma sintering[J]. ACS Applied Energy Materials, 2022, 5(9): 11662-11668. DOI: 10.1021/acsaem.2c02134.
15	LI D, LI J C, QIN X Y, et al. Thermoelectric performance for SnSe hot-pressed at different temperature[J]. Journal of Electronic Materials, 2017, 46(1): 79-84. DOI: 10.1007/s11664-016-4919-1.
16	ZHANG Q, CHERE E K, SUN J Y, et al. Studies on thermoelectric properties of n-type polycrystalline SnSe_1- xSx by iodine doping[J]. Advanced Energy Materials, 2015, 5(12): 1500360. DOI: 10. 1002/aenm.201500360.
17	GRASSO S, BIESUZ M, ZOLI L, et al. A review of cold sintering processes[J]. Advances in Applied Ceramics, 2020, 119(3): 115-143. DOI: 10.1080/17436753.2019.1706825.
18	GUO J, GUO H Z, BAKER A L, et al. Cold sintering: A paradigm shift for processing and integration of ceramics[J]. Angewandte Chemie (International Ed), 2016, 55(38): 11457-11461. DOI: 10.1002/anie.201605443.
19	ZHU B, SU X L, SHU S C, et al. Cold-sintered Bi₂Te₃-based materials for engineering nanograined thermoelectrics[J]. ACS Applied Energy Materials, 2022, 5(2): 2002-2010. DOI: 10.1021/acsaem.1c03540.
20	LU W B, WU S L, DING Q, et al. Cold sintering mediated engineering of polycrystalline SnSe with high thermoelectric efficiency[J]. ACS Applied Materials & Interfaces, 2024, 16(4): 4671-4678. DOI: 10.1021/acsami.3c15970.
21	SHI X, YANG J, SALVADOR J R, et al. Multiple-filled skutterudites: High thermoelectric figure of merit through separately optimizing electrical and thermal transports[J]. Journal of the American Chemical Society, 2011, 133(20): 7837-7846. DOI: 10.1021/ja111199y.
22	ZHAO Z H, PAN Z N, WEI F H, et al. Study on the properties of Ca₉Co₁₂O₂₈ under high pressure[J]. Ceramics International, 2021, 47(24): 34388-34395. DOI: 10.1016/j.ceramint.2021.08.351.
23	MONIKAPANI K, VIJAY V, ABINAYA R, et al. Realizing an enhanced Seebeck coefficient and extremely low thermal conductivity in anharmonic Sb-substituted SnSe nanostructures[J]. Journal of Alloys and Compounds, 2022, 923: 165961. DOI: 10.1016/j.jallcom.2022.165961.
24	TUOMISTO F. Open volume defects[M]//Semiconductors and Semimetals. Amsterdam: Elsevier, 2013: 39-65. DOI: 10.1016/b978-0-12-396489-2.00002-3.
25	LEIPNER H S, MIKHNOVICH V V, BONDARENKO V, et al. Positron annihilation of defects in silicon deformed at different temperatures[J]. Physica B: Condensed Matter, 2003, 340: 617-621. DOI: 10.1016/j.physb.2003.09.119.
26	CHIEN C H, CHANG C C, CHEN C L, et al. Facile chemical synthesis and enhanced thermoelectric properties of Ag doped SnSe nanocrystals[J]. RSC Advances, 2017, 7(54): 34300-34306. DOI: 10.1039/C7RA05819E.
27	HE H F, LI X F, CHEN Z Q, et al. Interplay between point defects and thermal conductivity of chemically synthesized Bi₂Te₃ nanocrystals studied by positron annihilation[J]. The Journal of Physical Chemistry C, 2014, 118(38): 22389-22394. DOI: 10. 1021/jp508085a.
28	LOU X N, LI S, CHEN X, et al. Lattice strain leads to high thermoelectric performance in polycrystalline SnSe[J]. ACS Nano, 2021, 15(5): 8204-8215. DOI: 10.1021/acsnano.1c01469.
29	ZHANG Q K, NING S T, QI N, et al. Enhanced thermoelectric performance of a simple method prepared polycrystalline SnSe optimized by spark plasma sintering[J]. 2019, 125(22): 225109. DOI: 10.1063/1.5095197.
30	LIU H L, ZHANG X, LI S H, et al. Synthesis and thermoelectric properties of SnSe by mechanical alloying and spark plasma sintering method[J]. Journal of Electronic Materials, 2017, 46(5): 2629-2633. DOI: 10.1007/s11664-016-4833-6.
31	MARTIN J, WANG L, CHEN L D, et al. Enhanced Seebeck coefficient through energy-barrier scattering in PbTe nanocomposites[J]. Physical Review B, 2009, 79(11): 115311. DOI: 10.1103/physrevb.79.115311.
32	SHANG P P, DONG J F, PEI J, et al. Highly textured N-type SnSe polycrystals with enhanced thermoelectric performance[J]. Research, 2019, 2019: 9253132. DOI: 10.34133/2019/9253132.
33	LIU D R, WANG D Y, HONG T, et al. Lattice plainification advances highly effective SnSe crystalline thermoelectrics[J]. Science, 2023, 380(6647): 841-846. DOI: 10.1126/science.adg7196.
34	PENG K L, LU X, ZHAN H, et al. Broad temperature plateau for high ZTs in heavily doped p-type SnSe single crystals[J]. Energy & Environmental Science, 2016, 9(2): 454-460. DOI: 10.1039/C5EE03366G.
35	JIN Y, WANG D Y, HONG T, et al. Outstanding CdSe with multiple functions leads to high performance of GeTe thermoelectrics[J]. Advanced Energy Materials, 2022, 12(10): 2103779. DOI: 10.1002/aenm.202103779.
36	WANG J L, WU J, WANG T, et al. T-square resistivity without Umklapp scattering in dilute metallic Bi₂O₂Se[J]. Nature Communications, 2020, 11(1): 3846. DOI: 10.1038/s41467-020-17692-6.
37	HE H F, ZHAO B, QI N, et al. Role of vacancy defects on the lattice thermal conductivity in In₂O₃ thermoelectric nanocrystals: A positron annihilation study[J]. Journal of Materials Science, 2018, 53(18): 12961-12973. DOI: 10.1007/s10853-018-2544-5.

[1]	WU Shijia, XIAO Xiang, WANG Chao, ZHONG Guobin, LI Xin, ZHENG Chao, RUAN Dianbo. Effect of high temperature heat treatment on electrochemical properties of three-dimensional porous graphene [J]. Energy Storage Science and Technology, 2020, 9(1): 65-69.
[2]	CHENG Xiaomin1,2, XU Kai1, ZHU Chuang1, YU Guoming2, LIU Zhi2. Inﬂuence of heat treatment on solidus temperature of LiNO3-NaNO3-KNO3 molten salt [J]. Energy Storage Science and Technology, 2017, 6(5): 1094-1098.