Speaker
Description
The thermoelectric properties of scandium nitride (ScN) thin films vary significantly with the experimental conditions [1,2]. In this context, it is well established that structural defects and chemical impurities play a crucial role, affecting the thermoelectric performance of ScN nanostructures [3,4]. Nevertheless, the underlying transport mechanisms and how they are affected remain unclear. Reported measurements show large variability, but strategies to enhance efficiency often yield conflicting results [4,5]. Recent progress has demonstrated the possibility of significantly reducing thermal transport in ScN thin films [6,7]; however, achieving an effective improvement in thermoelectric efficiency requires that this reduction is not neutralized by a decrease in the power factor.
In this presentation, using the Landauer-Büttiker approach, we analyze how different types of imperfections alter electronic and thermal transport in the ScN lattice. We analyze two types of defects: those that are commonly present and those that can be intentionally introduced to tailor transport properties. Among the latter, we examine the effects of the intentional substitution of scandium atoms with other metals, such as niobium, strontium and tungsten [8]. Among the former, we identify two dominant classes with opposing effects: (i) contiguous nitrogen vacancies, which enhance electrical conductivity but reduce the magnitude of the Seebeck coefficient (S), and (ii) oxygen substitutions coupled with nearby stacking faults, which increase the magnitude of S while hindering electrical conductivity [9].
References:
[1]. Phys. Rev. Mater. 3, 020301 (2019).
[2]. J. Mater. Chem. C 4, 3905 (2016).
[3]. Phys. Rev. B 86, 195140 (2012).
[4]. Phys. Rev. B 97, 085301 (2018).
[5]. J. Appl. Phys. 115, 153508 (2014).
[6]. Appl. Surf. Sci. Adv. 25, 100674 (2025).
[7]. ACS Appl. Energy Mater., 5 (9), 11025 (2022).
[8]. L. Cigarini et al., in preparation.
[9]. Appl. Surf. Sci. Adv. 31, 100923 (2026).