In this study, we report the effect of Zn doping on the thermoelectric properties of CO1-xZnxSbS0.85Se0.15 solid solutions （x = 0, 0.02, 0.05, 0.08）. The results show the dimensionless figure of merit （zT） increas...In this study, we report the effect of Zn doping on the thermoelectric properties of CO1-xZnxSbS0.85Se0.15 solid solutions （x = 0, 0.02, 0.05, 0.08）. The results show the dimensionless figure of merit （zT） increases from 0.17 to 0.34 at 875 K for Co0.95Zn0.05SbS0.85Se0.15 sample, due to the noticeable decrease in the lattice thermal conductivity by introducing point defect, which is further confirmed by an analysis based on the Debye-Callaway- Klemens model. Meanwhile, the thermoelectric power factor is maintained at high temperatures. This work highlights the important role of point defect in improving the thermoelectric performance of CoSbS-based compounds.展开更多
CoSbS-based compounds are good thermoelectric materials with low thermal conductivity and good electrical properties,which can effectively be used to improve the efficiency of many thermoelectric conversion processes....CoSbS-based compounds are good thermoelectric materials with low thermal conductivity and good electrical properties,which can effectively be used to improve the efficiency of many thermoelectric conversion processes.In order to improve their properties even more,in this study a series of experiments have been conducted in the frame of the traditional solid-phase synthesis and high-pressure method.It is shown that if the mass fluctuation and stress fluctuation in the considered CoSbS system increase,the scattering probability of phonons is enhanced and the lattice thermal conductivity of the material is reduced.Adding a small amount of Se can simultaneously optimize three thermoelectric properties,i.e.,the Seebeck coefficient is improved,the thermal conductivity becomes smaller and the quality factor grows.At the same time,the thermal and electrical properties of bulk materials can be optimized by using nano-scale Ni doped CoSbS samples.As shown by the experiments,Nidoped Co sites can effectively improve the carrier concentration,the effective mass of the density of states of the material,and the power factor.Under the same temperature conditions,the thermoelectric figure of merit(ZT)of Co1−yNiySbS1−xSex synthesized under high pressure,at x=0.15,y=0.1 is much higher than the corresponding value for CoSbS prepared by traditional methods.展开更多
CoSb3 nanowire arrays, preferred orientation of [510], were fabricated by electrodeposition of Co2+ and Sb3+ into anodic aluminum oxide (AAO) templates. The morphologies, structure, and composition of the as-synthesiz...CoSb3 nanowire arrays, preferred orientation of [510], were fabricated by electrodeposition of Co2+ and Sb3+ into anodic aluminum oxide (AAO) templates. The morphologies, structure, and composition of the as-synthesized sample have been performed using X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDS). Based on the previous investigation on CoSb3 nanowire arrays orientated along [420], the formation mechanism for different preferential orientation nanowire arrays was discussed.展开更多
In 1823,Thomas Seebeck first discovered the thermoelectric effect.A temperature difference across any electric conductor junction will generate a corresponding voltage difference.Probably the most familiar use of this...In 1823,Thomas Seebeck first discovered the thermoelectric effect.A temperature difference across any electric conductor junction will generate a corresponding voltage difference.Probably the most familiar use of this so called Seebeck effect is thermocouple.When an electric current passing through junction which is composed of two dissimilar conductors results in the absorption or release of the heat,this is the Peltier effect.This effect makes thermoelectric refrigerator or heating devices possible.Moreover a power generator can be also invented from the application of thermoelectric materials.Thermoelectric materials are those which possess high thermoelectric figure of merit.The major problem for thermoelectric materials is poor efficiency.They are now used only in the fields in which cost is not a big problem such as space and some other instruments.Thermoelectric materials are not widely used nowadays.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 11344010. 11404044 and 51472036)the Fundamental Research Funds for the Central Universities (No. 106112016CDJZR308808)
文摘In this study, we report the effect of Zn doping on the thermoelectric properties of CO1-xZnxSbS0.85Se0.15 solid solutions （x = 0, 0.02, 0.05, 0.08）. The results show the dimensionless figure of merit （zT） increases from 0.17 to 0.34 at 875 K for Co0.95Zn0.05SbS0.85Se0.15 sample, due to the noticeable decrease in the lattice thermal conductivity by introducing point defect, which is further confirmed by an analysis based on the Debye-Callaway- Klemens model. Meanwhile, the thermoelectric power factor is maintained at high temperatures. This work highlights the important role of point defect in improving the thermoelectric performance of CoSbS-based compounds.
基金This study greatly thanks to the support of Wuhan Technology and Business University,thanks to the research project from Natural Science Foundation of Hubei Province 2019.The item number is 2019CFC922.
文摘CoSbS-based compounds are good thermoelectric materials with low thermal conductivity and good electrical properties,which can effectively be used to improve the efficiency of many thermoelectric conversion processes.In order to improve their properties even more,in this study a series of experiments have been conducted in the frame of the traditional solid-phase synthesis and high-pressure method.It is shown that if the mass fluctuation and stress fluctuation in the considered CoSbS system increase,the scattering probability of phonons is enhanced and the lattice thermal conductivity of the material is reduced.Adding a small amount of Se can simultaneously optimize three thermoelectric properties,i.e.,the Seebeck coefficient is improved,the thermal conductivity becomes smaller and the quality factor grows.At the same time,the thermal and electrical properties of bulk materials can be optimized by using nano-scale Ni doped CoSbS samples.As shown by the experiments,Nidoped Co sites can effectively improve the carrier concentration,the effective mass of the density of states of the material,and the power factor.Under the same temperature conditions,the thermoelectric figure of merit(ZT)of Co1−yNiySbS1−xSex synthesized under high pressure,at x=0.15,y=0.1 is much higher than the corresponding value for CoSbS prepared by traditional methods.
基金Guizhou Provincial Department of Education Foundation(Qianjiaohe KYzi[2016]102)National Natural Science Foundation of China(51764005)Liupanshui Science and Technology Foundation(52020-2018-04-05)
文摘CoSb3 nanowire arrays, preferred orientation of [510], were fabricated by electrodeposition of Co2+ and Sb3+ into anodic aluminum oxide (AAO) templates. The morphologies, structure, and composition of the as-synthesized sample have been performed using X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDS). Based on the previous investigation on CoSb3 nanowire arrays orientated along [420], the formation mechanism for different preferential orientation nanowire arrays was discussed.
文摘In 1823,Thomas Seebeck first discovered the thermoelectric effect.A temperature difference across any electric conductor junction will generate a corresponding voltage difference.Probably the most familiar use of this so called Seebeck effect is thermocouple.When an electric current passing through junction which is composed of two dissimilar conductors results in the absorption or release of the heat,this is the Peltier effect.This effect makes thermoelectric refrigerator or heating devices possible.Moreover a power generator can be also invented from the application of thermoelectric materials.Thermoelectric materials are those which possess high thermoelectric figure of merit.The major problem for thermoelectric materials is poor efficiency.They are now used only in the fields in which cost is not a big problem such as space and some other instruments.Thermoelectric materials are not widely used nowadays.
