Improved thermoelectric performance of Ca0.25Nd0.25Sr0.35Ba0.15TiO3 ceramic via silver-induced breakage of double Schottky barrier

The double Schottky barriers in SrTiO 3 increase carrier scattering and restrict their transport, making their reduction or disruption critical for improving electrical performance. This study investigates a medium-entropy Ca 0.25 Nd 0.25 Sr 0.35 Ba 0.15 TiO 3 ceramic with low thermal conductivity, proposing that incorporating conductive nano-silver can disrupt these barriers via an electrical bridging effect. Results show that silver particles are distributed along grain boundaries, providing channels for reducing gases and enhancing the degree of reduction. The silver particles effectively weaken the double Schottky barriers, leading to a 261 % increase in carrier mobility compared to the sample without silver. As a result, the maximum electrical conductivity and power factor are enhanced by 68 % and 66 %, respectively. Eventually, the x = 9 wt% sample achieves a maximum zT of 0.25 at 900 K, representing a 28 % improvement. This study demonstrates that silver particles significantly enhance charge carrier transport and improve the thermoelectric performance of polycrystalline materials.