Effects of Ba filling fraction on the thermoelectric properties of p type filled skutterudite compounds Ba yFe 1.6 Co 2.4 Sb 12 (y=0-0.63) were investigated.Ba yFe 1.6 Co 2.4 Sb 12 showed p...Effects of Ba filling fraction on the thermoelectric properties of p type filled skutterudite compounds Ba yFe 1.6 Co 2.4 Sb 12 (y=0-0.63) were investigated.Ba yFe 1.6 Co 2.4 Sb 12 showed p type conduction.The hall coefficient (R H) and seebeck coefficient(α) increased with increasing Ba filling fraction.But hole concentration (p) and electrical conductivity (σ) decreased.While Ba filling fraction was about 0.4,the lattice thermal conductivity (κ L) reached the minimum value.The results show that effect of Ba rattling on phonon scattering is the strongest as Sb icosahedron partial voids are filled by Ba.A maximum dimensionless thermoelectric figure of merit (ZT) value of 0.7 was obtained for Ba 0.38 Fe 1.6 Co 2.4 Sb 12 at 750K.展开更多
Yttrium-filled sku, tterudites Yy Fex Co4-x Sb12 （ Y =0- 0. 40 ） were synthesized. The effect of Y filling fraction on thermoelectric properties of Yy Fex Co4-x Sb12 was investigated. All samples showed p-type condu...Yttrium-filled sku, tterudites Yy Fex Co4-x Sb12 （ Y =0- 0. 40 ） were synthesized. The effect of Y filling fraction on thermoelectric properties of Yy Fex Co4-x Sb12 was investigated. All samples showed p-type conduct. The electrical conductivity decreased with increasing filling fraction y. The Seebeck coefficient inreased with increasing temperature. The lattice thermal conductivity decreased with increasing filling fraction y and showed the minimum value at a certain filling fraction y = 0.3. The effect of different filling atoms M（ M： Ba, Ce, Y） on the lattice thermal conductivity of MyFexCo4-xSb12 was discussed. The maximum ZT value of O. 7 was obtained for Y0.06 Fe0.7 Co3.3 Sb12 at 750 K.展开更多
In this paper, we propose a methodology to maximize the absorption bandwidth of a metal-insulator-metal(MIM) based absorber. The proposed structure is made of a Cr-Al_2O_3-Cr multilayer design. At the initial step,the...In this paper, we propose a methodology to maximize the absorption bandwidth of a metal-insulator-metal(MIM) based absorber. The proposed structure is made of a Cr-Al_2O_3-Cr multilayer design. At the initial step,the optimum MIM planar design is fabricated and optically characterized. The results show absorption above 0.9 from 400 nm to 850 nm. Afterward, the transfer matrix method is used to find the optimal condition for the perfect light absorption in an ultra-broadband frequency range. This modeling approach predicts that changing the filling fraction of the top Cr layer can extend light absorption toward longer wavelengths. We experimentally proved that the use of proper top Cr thickness and annealing temperature leads to a nearly perfect light absorption from 400 nm to 1150 nm, which is much broader than that of a planar design. Therefore, while keeping the overall process lithography-free, the absorption functionality of the design can be significantly improved. The results presented here can serve as a beacon for future performance-enhanced multilayer designs where a simple fabrication step can boost the overall device response without changing its overall thickness and fabrication simplicity.展开更多
基金ThisworkwaspartiallysupportedbyaGrant in AidforEncouragementofYoungScientists (A) (No .12 75 0 5 91) Japan .ThisworkwasalsosupportedpartiallybytheResearchFoundationforMaterialsScience apan
文摘Effects of Ba filling fraction on the thermoelectric properties of p type filled skutterudite compounds Ba yFe 1.6 Co 2.4 Sb 12 (y=0-0.63) were investigated.Ba yFe 1.6 Co 2.4 Sb 12 showed p type conduction.The hall coefficient (R H) and seebeck coefficient(α) increased with increasing Ba filling fraction.But hole concentration (p) and electrical conductivity (σ) decreased.While Ba filling fraction was about 0.4,the lattice thermal conductivity (κ L) reached the minimum value.The results show that effect of Ba rattling on phonon scattering is the strongest as Sb icosahedron partial voids are filled by Ba.A maximum dimensionless thermoelectric figure of merit (ZT) value of 0.7 was obtained for Ba 0.38 Fe 1.6 Co 2.4 Sb 12 at 750K.
基金Funded by National Natural Science Foundation of China (No.50372049)
文摘Yttrium-filled sku, tterudites Yy Fex Co4-x Sb12 （ Y =0- 0. 40 ） were synthesized. The effect of Y filling fraction on thermoelectric properties of Yy Fex Co4-x Sb12 was investigated. All samples showed p-type conduct. The electrical conductivity decreased with increasing filling fraction y. The Seebeck coefficient inreased with increasing temperature. The lattice thermal conductivity decreased with increasing filling fraction y and showed the minimum value at a certain filling fraction y = 0.3. The effect of different filling atoms M（ M： Ba, Ce, Y） on the lattice thermal conductivity of MyFexCo4-xSb12 was discussed. The maximum ZT value of O. 7 was obtained for Y0.06 Fe0.7 Co3.3 Sb12 at 750 K.
基金Türkiye Bilimsel ve Teknolojik Arastirma Kurumu(TüBITAK)DPT-HAMIT(109E301,113E331)Türkiye Bilimler Akademisi(TUBA)
文摘In this paper, we propose a methodology to maximize the absorption bandwidth of a metal-insulator-metal(MIM) based absorber. The proposed structure is made of a Cr-Al_2O_3-Cr multilayer design. At the initial step,the optimum MIM planar design is fabricated and optically characterized. The results show absorption above 0.9 from 400 nm to 850 nm. Afterward, the transfer matrix method is used to find the optimal condition for the perfect light absorption in an ultra-broadband frequency range. This modeling approach predicts that changing the filling fraction of the top Cr layer can extend light absorption toward longer wavelengths. We experimentally proved that the use of proper top Cr thickness and annealing temperature leads to a nearly perfect light absorption from 400 nm to 1150 nm, which is much broader than that of a planar design. Therefore, while keeping the overall process lithography-free, the absorption functionality of the design can be significantly improved. The results presented here can serve as a beacon for future performance-enhanced multilayer designs where a simple fabrication step can boost the overall device response without changing its overall thickness and fabrication simplicity.
