The thermoelectric materials have been considered as a potential candidate for the new power generation technology based on their reversible heat and electricity conversion.Lead telluride（Pb Te） is regarded as an ex...The thermoelectric materials have been considered as a potential candidate for the new power generation technology based on their reversible heat and electricity conversion.Lead telluride（Pb Te） is regarded as an excellent mid-temperature thermoelectric material due to its suitable intrinsic thermoelectric properties.So tremendous efforts have been done to improve the thermoelectric performance of Pb Te,and figures of merit,zT 〉 2.0,have been reported.Main strategies for optimizing the thermoelectric performance have been focused as the main line of this review.The band engineering and phonon scattering engineering as two main effective strategies are systemically summarized here.The band engineering,like band convergence,resonant levels,and band flatting have been addressed in improving the power factor.Additionally,phonon scattering engineerings,such as atomic-scale,nano-scale,meso-scale,and multi-scale phonon scatterings have been applied to reduce the thermal conductivity.Besides,some successful synergistic effects based on band engineerings and phonon scatterings are illustrated as a simultaneous way to optimize both the power factor and thermal conductivity.Summarizing the above three main parts,we point out that the synergistic effects should be effectively exploited,and these may further boost the thermoelectric performance of Pb Te alloys and can be extended to other thermoelectric materials.展开更多
The formation of the Mn/Pb Te（111） interface is investigated by photoemission spectrum. The core level behavior of Mn 2p is consistent with Mn substitutional adsorption during the initial Mn deposition, forming a（...The formation of the Mn/Pb Te（111） interface is investigated by photoemission spectrum. The core level behavior of Mn 2p is consistent with Mn substitutional adsorption during the initial Mn deposition, forming a（√3 ×√3）R30？-Pb0.67Mn0.33 Te phase of the second layer. Further deposition of Mn can cause metallic Mn islands to cover the substitutional substrate. Ultraviolet photoemission measurements show that the Fermi level is shifted into the conduction band, indicating Ohmic contact formation at the Mn/Pb Te（111） interface. The valence band maximum associated with the Pb0.67Mn0.33 Te layer is located at 1.27 e V below the Fermi level, and a schematic electronic structure of the Mn/Pb Te（111）interface is given. The work function of the substituted substrate with Pb-covered Mn islands is determined to be 4.16 e V,in comparison with 4.35 e V for the Pb-covered substituted substrate and 3.95 e V for the pristine Pb Te（111） surface.展开更多
A new theoretical interpretation for the anomalous quantum size effects in PbTe-Bi superlattices has been proposed.The calculated thickness of Bi layers at which the semimetal-semiconductor transition occurs is in goo...A new theoretical interpretation for the anomalous quantum size effects in PbTe-Bi superlattices has been proposed.The calculated thickness of Bi layers at which the semimetal-semiconductor transition occurs is in good agreement with the experimental data.展开更多
The microdefects in Te-rich PbTe coating material grown by Bridgman technique have been studied via transmission electron microscopy.The results indicate that the major microdefects in Te-rich PbTe crystal are plate-l...The microdefects in Te-rich PbTe coating material grown by Bridgman technique have been studied via transmission electron microscopy.The results indicate that the major microdefects in Te-rich PbTe crystal are plate-like defects lying on{100}plane and homogeneously distributed in the matrix with density about 1.7×10^(16)/cm^(3).They are originated from the precipitation of native point defects in Te-rich PbTe which occured in the cooling and annealing process and presented in the form of plates consisting of Te anti-site atoms or interstitial Te atoms.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2013CB632506)the National Natural Science Foundation of China(Grant Nos.51501105,51672159,and 51611540342)+4 种基金the Young Scholars Program of Shandong University(Grant No.2015WLJH21)the China Postdoctoral Science Foundation(Grant Nos.2015M580588 and 2016T90631)the Postdoctoral Innovation Foundation of Shandong Province,China(Grant No.201603027)the Fundamental Research Funds of Shandong University(Grant No.2015TB019)the Foundation of the State Key Laboratory of Metastable Materials Science and Technology(Grant No.201703)
文摘The thermoelectric materials have been considered as a potential candidate for the new power generation technology based on their reversible heat and electricity conversion.Lead telluride（Pb Te） is regarded as an excellent mid-temperature thermoelectric material due to its suitable intrinsic thermoelectric properties.So tremendous efforts have been done to improve the thermoelectric performance of Pb Te,and figures of merit,zT 〉 2.0,have been reported.Main strategies for optimizing the thermoelectric performance have been focused as the main line of this review.The band engineering and phonon scattering engineering as two main effective strategies are systemically summarized here.The band engineering,like band convergence,resonant levels,and band flatting have been addressed in improving the power factor.Additionally,phonon scattering engineerings,such as atomic-scale,nano-scale,meso-scale,and multi-scale phonon scatterings have been applied to reduce the thermal conductivity.Besides,some successful synergistic effects based on band engineerings and phonon scatterings are illustrated as a simultaneous way to optimize both the power factor and thermal conductivity.Summarizing the above three main parts,we point out that the synergistic effects should be effectively exploited,and these may further boost the thermoelectric performance of Pb Te alloys and can be extended to other thermoelectric materials.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11074214,51202149,and 11204180)the Natural Science Foun-dation of Zhejiang Province,China(Grant No.LQ12F04001)+1 种基金the Scientific Research Fund of Zhejiang Provincial Education Department,China(Grant No.Y201121234)the Ministry of Science and Technology of China
文摘The formation of the Mn/Pb Te（111） interface is investigated by photoemission spectrum. The core level behavior of Mn 2p is consistent with Mn substitutional adsorption during the initial Mn deposition, forming a（√3 ×√3）R30？-Pb0.67Mn0.33 Te phase of the second layer. Further deposition of Mn can cause metallic Mn islands to cover the substitutional substrate. Ultraviolet photoemission measurements show that the Fermi level is shifted into the conduction band, indicating Ohmic contact formation at the Mn/Pb Te（111） interface. The valence band maximum associated with the Pb0.67Mn0.33 Te layer is located at 1.27 e V below the Fermi level, and a schematic electronic structure of the Mn/Pb Te（111）interface is given. The work function of the substituted substrate with Pb-covered Mn islands is determined to be 4.16 e V,in comparison with 4.35 e V for the Pb-covered substituted substrate and 3.95 e V for the pristine Pb Te（111） surface.
文摘A new theoretical interpretation for the anomalous quantum size effects in PbTe-Bi superlattices has been proposed.The calculated thickness of Bi layers at which the semimetal-semiconductor transition occurs is in good agreement with the experimental data.
文摘The microdefects in Te-rich PbTe coating material grown by Bridgman technique have been studied via transmission electron microscopy.The results indicate that the major microdefects in Te-rich PbTe crystal are plate-like defects lying on{100}plane and homogeneously distributed in the matrix with density about 1.7×10^(16)/cm^(3).They are originated from the precipitation of native point defects in Te-rich PbTe which occured in the cooling and annealing process and presented in the form of plates consisting of Te anti-site atoms or interstitial Te atoms.
