A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition techniq...A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.展开更多
The light beating technique (intensity correlation algorithm) was employed to analyze the Rayleigh scattering from the roughened Ag electrode in very dilute (10^(-4)M) pyrazine, pyridine and piperidine aqueous solutio...The light beating technique (intensity correlation algorithm) was employed to analyze the Rayleigh scattering from the roughened Ag electrode in very dilute (10^(-4)M) pyrazine, pyridine and piperidine aqueous solutions containing KCl (0.1 M). The relaxation time is longer when the applied voltages are between-0.4 V and-0.8 V(vs. SCE) where the Raman effect also shows greater surface enhancement. Also observed was that for the piperidine case the relaxation time reaches its maximum at the more negative applied voltage. The origin of the relaxation is attributed mainly to the desorp- tion process of the pyrazine. pyridine and piperidine molecules off the roughened Ag electrode. An. electrostatic model was also proposed for the interpretation of these experimental observations.展开更多
基金Supported by the Scientific Research Deanship of University of Dammam under Grant No 2014264
文摘A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.
基金This work was supported by the National Natural Science Foundation of ChinaNational Laboratory for Structural Chemistry of Dynamical and Stable Species.
文摘The light beating technique (intensity correlation algorithm) was employed to analyze the Rayleigh scattering from the roughened Ag electrode in very dilute (10^(-4)M) pyrazine, pyridine and piperidine aqueous solutions containing KCl (0.1 M). The relaxation time is longer when the applied voltages are between-0.4 V and-0.8 V(vs. SCE) where the Raman effect also shows greater surface enhancement. Also observed was that for the piperidine case the relaxation time reaches its maximum at the more negative applied voltage. The origin of the relaxation is attributed mainly to the desorp- tion process of the pyrazine. pyridine and piperidine molecules off the roughened Ag electrode. An. electrostatic model was also proposed for the interpretation of these experimental observations.
