As a sister compound of PbTe, SnTe possesses the environmentally friendly elements. However, the pristine SnTe compounds suffer from the high carrier concentration, the large valence band offset between the L and Σpo...As a sister compound of PbTe, SnTe possesses the environmentally friendly elements. However, the pristine SnTe compounds suffer from the high carrier concentration, the large valence band offset between the L and Σpositions and high thermal conductivity. Using high-pressure and high-temperature technology, we synthesized the pristine SnTe samples at different pressures and systemically investigated their thermoelectric properties.High pressure induces rich microstructures, including the high-density dislocations and lattice distortions, which serve as the strong phonon scattering centers, thereby reducing the lattice thermal conductivity. For the electrical properties, pressure reduces the harmful high carrier concentration, due to the depression of Sn vacancies.Moreover, pressure induces the valence band convergence, reducing the energy separation between the L and Σpositions. The band convergence and suppressed carrier concentration increase the Seebeck coefficient. Thus, the power factors of pressure-sintered compounds do not deteriorate significantly under the condition of decreasing electrical conductivity. Ultimately, for a pristine SnTe compound synthesized at 5 GPa, a higher ZT value of 0.51 is achieved at 750 K, representing a 140% improvement compared to the value of 0.21 obtained using SPS. Therefore, the high-pressure and high-temperature technology is demonstrated as an effectively approach to optimize thermoelectric performance.展开更多
High pressure and high temperature(HPHT)technology,as an extreme physical condition,plays an important role in regulating the properties of materials,having the advantages of enhancing doping efficiency,refining grain...High pressure and high temperature(HPHT)technology,as an extreme physical condition,plays an important role in regulating the properties of materials,having the advantages of enhancing doping efficiency,refining grain size,and manufacturing defects,therefore it is quite necessary to study the effectiveness on tuning thermoelectric properties.Elemental telluride,a potential candidate for thermoelectric materials,has the poor doping efficiency and high resistivity,which become an obstacle for practical applications.Here,we report the realization of a dual optimization of electrical behaviors and thermal conductivity through HPHT method combining with the introduction of black phosphorus.The results show the maximum zT of 0.65 and an average zT of 0.42(300 K–610 K),which are increased by 55%and 68%in the synthesis pressure regulation system,respectively.This study clarifies that the HPHT method has significant advantages in modulating the thermoelectric parameters,providing a reference for seeking high performance thermoelectric materials.展开更多
SWOT(Surface Water and Ocean Topography)测高卫星已经被美国国家研究委员会推荐为"未来10年NASA承担的地球科学和应用的国家重点计划",它通过获取的高精度、高空间分辨率的海洋表面高(Sea Surface Heights,SSH)和陆地水高(...SWOT(Surface Water and Ocean Topography)测高卫星已经被美国国家研究委员会推荐为"未来10年NASA承担的地球科学和应用的国家重点计划",它通过获取的高精度、高空间分辨率的海洋表面高(Sea Surface Heights,SSH)和陆地水高(Terrestrial Water Heights,TWH),监测海洋变化和陆地水文变化。SWOT卫星将使测高卫星由传统的一维、沿轨的剖面测高过渡到二维的宽刈幅干涉测高。与传统测高卫星脉冲有限式的测量方式相比,SWOT通过合成孔径雷达干涉测量使空间分辨率提高了一个数量级,一旦成功,它将在海洋和陆地、甚至军事方面都将具有广泛的应用前景,并为宽刈幅测高卫星设立众多技术标准,对我国宽刈幅卫星的发展具有重要的借鉴。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 12374012, 11974208, 52172212, and 52002217)Shandong Provincial Natural Science Foundation (Grant Nos. ZR2023JQ001, ZR2020YQ05, and 2019KJJ020)financial support from the Program of Distinguished Expert of Taishan Scholar (Grant No. tstp20221124)。
文摘As a sister compound of PbTe, SnTe possesses the environmentally friendly elements. However, the pristine SnTe compounds suffer from the high carrier concentration, the large valence band offset between the L and Σpositions and high thermal conductivity. Using high-pressure and high-temperature technology, we synthesized the pristine SnTe samples at different pressures and systemically investigated their thermoelectric properties.High pressure induces rich microstructures, including the high-density dislocations and lattice distortions, which serve as the strong phonon scattering centers, thereby reducing the lattice thermal conductivity. For the electrical properties, pressure reduces the harmful high carrier concentration, due to the depression of Sn vacancies.Moreover, pressure induces the valence band convergence, reducing the energy separation between the L and Σpositions. The band convergence and suppressed carrier concentration increase the Seebeck coefficient. Thus, the power factors of pressure-sintered compounds do not deteriorate significantly under the condition of decreasing electrical conductivity. Ultimately, for a pristine SnTe compound synthesized at 5 GPa, a higher ZT value of 0.51 is achieved at 750 K, representing a 140% improvement compared to the value of 0.21 obtained using SPS. Therefore, the high-pressure and high-temperature technology is demonstrated as an effectively approach to optimize thermoelectric performance.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11804185,11974208,52172212,52102335,and 52002217)the Natural Science Foundation of Shandong Province,China(Grant Nos.ZR2020YQ05,ZR2019MA054,2019KJJ020,ZR2021YQ03,and 2022KJA043)。
文摘High pressure and high temperature(HPHT)technology,as an extreme physical condition,plays an important role in regulating the properties of materials,having the advantages of enhancing doping efficiency,refining grain size,and manufacturing defects,therefore it is quite necessary to study the effectiveness on tuning thermoelectric properties.Elemental telluride,a potential candidate for thermoelectric materials,has the poor doping efficiency and high resistivity,which become an obstacle for practical applications.Here,we report the realization of a dual optimization of electrical behaviors and thermal conductivity through HPHT method combining with the introduction of black phosphorus.The results show the maximum zT of 0.65 and an average zT of 0.42(300 K–610 K),which are increased by 55%and 68%in the synthesis pressure regulation system,respectively.This study clarifies that the HPHT method has significant advantages in modulating the thermoelectric parameters,providing a reference for seeking high performance thermoelectric materials.
文摘SWOT(Surface Water and Ocean Topography)测高卫星已经被美国国家研究委员会推荐为"未来10年NASA承担的地球科学和应用的国家重点计划",它通过获取的高精度、高空间分辨率的海洋表面高(Sea Surface Heights,SSH)和陆地水高(Terrestrial Water Heights,TWH),监测海洋变化和陆地水文变化。SWOT卫星将使测高卫星由传统的一维、沿轨的剖面测高过渡到二维的宽刈幅干涉测高。与传统测高卫星脉冲有限式的测量方式相比,SWOT通过合成孔径雷达干涉测量使空间分辨率提高了一个数量级,一旦成功,它将在海洋和陆地、甚至军事方面都将具有广泛的应用前景,并为宽刈幅测高卫星设立众多技术标准,对我国宽刈幅卫星的发展具有重要的借鉴。
