Simulation of thermoelectric materials efficiency: The case study of Sr1−xYxTiO3 thermoelectric ceramic

Nowadays, production of thermoelectric ceramics with high efficiency (high figure-of-merit or ZT) is one of the main concerns for the researchers. However, many challenges have arisen due to inadequate knowledge about the influence of each process parameter on ZT. In the present research, we attempted for the first time to scrutinize the way each parameter influences the efficiency of thermoelectric ceramics. We also tried to estimate the percentage of the dependency of efficiency on these parameters. For this purpose, a case study has been done on the Sr1−xYxTiO3 thermoelectric ceramic. Different methods of synthesis as well as all the parameters affecting the efficiency were simulated. The simulation was carried out by gene expression programming (GEP). Accordingly, 10 different models were suggested and their adequacy for measuring the ZT value of Sr1−xYxTiO3 thermoelectric ceramic was examined. The eighth GEP model was eventually selected as the most appropriate model. On the basis of GEP, 3D, data, and frequency simulations were carried out and the obtained results were compared. The results of data simulation indicated that ZT has minimum dependency on compact pressure and the sintering temperature and that it has maximum dependency on the process temperature and the additive content. In comparison, as a consequence of frequency simulation, it was revealed that ZT has minimum dependency on the sintering temperature and maximum dependency on the sintering time and the additive content. Also, the 3D analyses demonstrated a better performance by combustion synthesis in comparison with other synthesis routes.