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本文采用化学共沉淀和固相反应相结合的方法,制备掺杂和不掺杂的具有反尖晶石结构的锡和锌复合氧化物,还比较详细地研究了它的电导与氧分压、温度和掺杂物之间的关系以及相应的缺陷结构.并根据Seebeck 效应的测定推测其在700°—900℃的范围内具有小极化子的热激活跃迁机制. 相似文献
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In this paper,we report that the thermoelectric performance of n-type Pb Se could be improved through synergistically optimizing electrical and thermal transport properties via Sb doping and Mg alloying.The carrier concentration was firstly optimized through Sb doping,resulting in a maximum power factor of~15.4μW cm~(-1)K~(-2)and maximum ZT of~0.9 at 873 K in Pb_(0.99)Sb_(0.01)Se.Then,Mg was selected for alloying in Pb sites to produce point defects,which can largely intensify the phonon scattering and lower thermal conductivity.After Mg alloying,the thermal conductivity at 300 K(873 K)was significantly suppressed from~4.6 Wm~(-1)K~(-1)(1.5 Wm~(-1)K~(-1))for Pb_(0.99)Sb_(0.01)Se to~2.9 Wm~(-1)K~(-1)(1.1 Wm~(-1)K~(-1))for Pb_(0.99)Sb_(0.01)Se-6%Mg Se.Through combining Sb doping and Mg alloying,a maximum ZT of~1.1 was achieved at 873 K for Pb_(0.99)Sb_(0.01)Se-6%Mg Se,and the average ZT(ZT_(ave))was increased by 28.6%from~0.42 for Pb_(0.99)Sb_(0.01)Se to~0.54 for Pb_(0.99)Sb_(0.01)Se-6%Mg Se.The results indicate that Pb Se is a robust candidate for medium-temperature thermoelectric applications. 相似文献
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《自然科学进展(英文版)》2022,32(5):586-593
In this study, β-Cu2+xSe/SiC nano-multilayer films with different modulation period were successfully deposited on SiO2/Si substrates by sputtering alternately using Cu–Se and SiC targets. The deposited films were observed on both surface and cross-section, and the thermoelectric properties were studied. The results show that both carrier concentration and mobility at room temperature decreased with the reducing modulation period for the nano-multilayer films. The conductivity slightly decreased and Seebeck coefficient greatly increased with the reducing modulation period. As a result of competition, the power factor of the nano multilayer films increased with the reducing modulation period because the positive effect of the Seebeck coefficient exceeded the negative effect of the conductivity. In the case of β-Cu2+xSe/SiC nano multilayer film with the smallest modulation periods (210 ?nm), the power factor reached 0.39 ?mWm?1K?2 and 0.59 ?mWm?1K?2 at room temperature and 325 ?°C, respectively. The enhanced power factor for nano multilayer films is attributed to the scattering process at the β-Cu2+xSe/SiC layer interface, which reduces the carrier concentration and the mobility. It is concluded that the thermoelectric properties of β-Cu2+xSe films can be effectively improved by designing nano multilayer structure. 相似文献
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采用固相反应法与无压烧结法相结合制备了ABO3型钙钛矿(Nd0.62Li0.15)TiO3晶体陶瓷材料,并对其热电性能进行了表征.高分辨率透射电镜观察显示,制备的材料具有纳米超晶格结构,导致材料表现出玻璃态热传导特征且热导率小于2W/(m·K),该玻璃态热传导源于超晶格结构形成的大量纳米域界面对声子的强烈散射.A位空位填充使材料的电子电导率得到了明显改善,但对材料的热导率影响不大.塞贝克系数因为TiO6八面体的扭曲而受到一定的影响.在测试温度范围内,块体陶瓷在500K时得到了最高的无因次热电优值(ZT)0.019. 相似文献
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Yan Yun’an 《华南师范大学学报(自然科学版)》2014,(6):136-137
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with 相似文献
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介绍了NaxCo2O4氧化物热电材料的基本结构和热电性能,论述了NaxCo2O4热电材料的研究进展,并对NaxCo2O4材料的Na位掺杂(掺入K,Sr,Y,Nd,Sm,Yb,Ca,Ag)和Co位掺杂(掺入Ti,Rh,Pd,Pb,Mn,Ru)进行了评述·不同元素对Na位和Co位的掺杂效果的影响是不同的,但可以看出NaxCo2O4热电材料的掺杂研究有着非常好的研究价值和应用前景· 相似文献
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Based on the Boltzmann transport equation of electrons and taking the scattering effect of electrons in the grain boundary as the boundary conditions of electrons transport in the grain, we presented a theoretical model for the Seebeck coefficient of bulk poly- crystalline thermoelectric materials, and applied it to studying the grain size effect on the Seebeck coefficient. Then we discussed the effects of transmissivity, temperature and the mean free path of electrons on the size effect. The results show t... 相似文献
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