Flexible ternary carbon black/Bi_(2)Te_(3) based alloy/polylactic acid(CB/BTBA/PLA)composites were fabricated by additive manufacturing and their thermoelectric properties were investigated from 300 K to 360 K.At 300 ...Flexible ternary carbon black/Bi_(2)Te_(3) based alloy/polylactic acid(CB/BTBA/PLA)composites were fabricated by additive manufacturing and their thermoelectric properties were investigated from 300 K to 360 K.At 300 K,as the mass ratios of BTBAs in the composites increased from 38.5% to 71.4%,both the electrical conductivity and Seebeck coefficient of the composites increased from 5.8 S/cm to 13.3 S/cm,and from 60.2 mV/K to 119.9 mV/K,respectively,and the thermal conductivity slightly increased from 0.15 W m^(-1)K^(-1) to 0.25 W m^(-1)K^(-1),as a result,the ZT value of the composites increased from 0.004 to 0.023.As the temperature increased from 300 K to 360 K,the electrical conductivity of all the composites slightly decreased,while the thermal conductivity slowly increased,and a highest ZT value of 0.024 was achieved for the composites with 71.4% BTBAs at 320 K.Unlike traditional sterolithography,fused deposition modeling,selective laser melting,etc.,this additive manufacturing process can directly print the solutions which contain inorganic fillers and polymer matrixes into almost any designed intricate geometries of thermoelectric composites,therefore this process has great potential to be used for fabrication of flexible polymer based thermoelectric composites and devices.展开更多
The transport properties of artificially engineered superlattices （SLs） can be tailored by incorporating a high density of interfaces in them. Specifically, SiGe SLs with low thermal conductivity values have great p...The transport properties of artificially engineered superlattices （SLs） can be tailored by incorporating a high density of interfaces in them. Specifically, SiGe SLs with low thermal conductivity values have great potential for thermoelectric generation and nano-cooling of Si-based devices. Here, we present a novel approach for customizing thermal transport across nanostructures by fabricating Si/Sil-xGex SLs with well-defined compositional gradients across the SiGe layer from x = 0 to 0.60. We demonstrate that the spatial inhomogeneity of the structure has a remarkable effect on the heat-flow propagation, reducing the thermal conductivity to -2.2 W.m-1.K-1, which is significantly less than the values achieved previously with non-optimized long-period SLs. This approach offers further possibilities for future applications in thermoelectricity.展开更多
基金supported by the Shanghai Innovation Action Plan Project(17090503600)the National Natural Science Foundation of China(11811530636,61504081,61611530550)+4 种基金the Program for Professor of Special Appointment(Young Eastern Scholar Program)at Shanghai Institutions of Higher Learning(QD2015039)support from the Swedish Research Council under project no.2016-3365the Swedish Energy Agency under project 46519-1the Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows programthe Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University(Faculty Grant SFO-Mat-LiU No.200900971).
文摘Flexible ternary carbon black/Bi_(2)Te_(3) based alloy/polylactic acid(CB/BTBA/PLA)composites were fabricated by additive manufacturing and their thermoelectric properties were investigated from 300 K to 360 K.At 300 K,as the mass ratios of BTBAs in the composites increased from 38.5% to 71.4%,both the electrical conductivity and Seebeck coefficient of the composites increased from 5.8 S/cm to 13.3 S/cm,and from 60.2 mV/K to 119.9 mV/K,respectively,and the thermal conductivity slightly increased from 0.15 W m^(-1)K^(-1) to 0.25 W m^(-1)K^(-1),as a result,the ZT value of the composites increased from 0.004 to 0.023.As the temperature increased from 300 K to 360 K,the electrical conductivity of all the composites slightly decreased,while the thermal conductivity slowly increased,and a highest ZT value of 0.024 was achieved for the composites with 71.4% BTBAs at 320 K.Unlike traditional sterolithography,fused deposition modeling,selective laser melting,etc.,this additive manufacturing process can directly print the solutions which contain inorganic fillers and polymer matrixes into almost any designed intricate geometries of thermoelectric composites,therefore this process has great potential to be used for fabrication of flexible polymer based thermoelectric composites and devices.
文摘The transport properties of artificially engineered superlattices （SLs） can be tailored by incorporating a high density of interfaces in them. Specifically, SiGe SLs with low thermal conductivity values have great potential for thermoelectric generation and nano-cooling of Si-based devices. Here, we present a novel approach for customizing thermal transport across nanostructures by fabricating Si/Sil-xGex SLs with well-defined compositional gradients across the SiGe layer from x = 0 to 0.60. We demonstrate that the spatial inhomogeneity of the structure has a remarkable effect on the heat-flow propagation, reducing the thermal conductivity to -2.2 W.m-1.K-1, which is significantly less than the values achieved previously with non-optimized long-period SLs. This approach offers further possibilities for future applications in thermoelectricity.
