| Processing and Enhancement of Thermoelectric performance ZnO Ceramics |
| Paper ID : 1050-ISCH |
| Authors |
|
Fouad Zahran * Faculty of Science Helwan University |
| Abstract |
| A comprehensive exploration of the intricate interplay between sintering conditions, niobium oxide impurity concentrations, and their collective impact on the processing, microstructure and thermoelectric performance of ZnO ceramics. The ZnO-based ceramics were prepared with varying amounts of Nb doping (0 to 0.25 wt. %) and sintered at 1450°C for 2 hours in reduced atmosphere. Different characterizations have been investigated to identify the performance profile of the investigated ceramics such as; phase analysis, densification and microstructure. Thermal conductivity and thermoelectric properties of the investigated ceramics were evaluated in the temperature range of 100–800 °C. Addition of Nb to ZnO ceramics gave a harmonic structure resulting from homogenous/complete solid solution diffusion reaction. Thermal conductivity, electrical resistivity and thermoelectric properties were promoted with their highest values at 0.15 wt. % Nb doping. ZnO doped ceramics gave identical behavior of the n-type semiconductors with outstanding thermoelectric properties at high temperatures. Our results indicate that native defects such as oxygen vacancies (VO) decrease the band gap energy values and increase the carrier concentration, improving electrical conductivity and power factor. The findings showed that the sintered NZO ceramic with 0.15 wt% Nb doping had the best overall properties. This suggests that Nb-doping ZnO in argon is a viable and practical approach for improving its thermoelectric performance. |
| Keywords |
| Thermoelectric materials; ZnO ceramics; Microstructure; Thermal conductivity; Energy band gap. |
| Status: Abstract Accepted (Oral Presentation) |