Tailoring the interfacial properties at the nanoscale is essential for improving the performance of thermoelectric materials, where the simultaneous optimization of electronic and phononic transport remains a key challenge. We used atomic layer deposition (ALD) to conformally coat Bi2Te3Se0.3 (BTS) powders with TiO2-ZnO multilayer oxides. Two configurations were fabricated: ZnO/TiO2 bilayers (2 nm thick) and ZnO/TiO2/ZnO/TiO2 multilayers (1 nm thick). The coated powders were consolidated by spark plasma sintering (SPS). The ALD-grown multilayers uniformly coated the powder and remained highly dense after sintering. Consequently, the multilayer-coated structure showed improved carrier concentration and mobility owing to interfacial electron donation and diffusion doping, enhancing electrical conductivity. Their high-density and continuous layers effectively reduce lattice thermal conductivity, resulting in a zT of 0.8 at 460 K, a 27% increase over uncoated BTS. The controlled interface design enabled effective tuning of both charge carrier and phonon transport. This study demonstrates that conformal interfacial engineering via ALD is a promising strategy for enhancing thermoelectric performance by simultaneously tuning the electronic and phononic transport properties through nanoscale interface design.
KW - Thermoelectrics KW - atomic layer deposition KW - interface engineering KW - multilayer DO - 10.20517/microstructures.2025.120 UR - https://dx.doi.org/10.20517/microstructures.2025.120