Solution-Processed, Surface-Engineered, Polycrystalline CdSe-SnSe Exhibiting Low Thermal Conductivity

Our group focused on developing materials for energy-related applications, emphasizing energy storage and thermal electricity. We used nano crystals as building blocks, or precursors for constructing the microscopic materials. And we investigate the transformation the nano crystals undergo into whole solids, aiming to enhance performance, and by understanding and controlling the properties derived from the nanoscale features.

In particular, for thermal electric materials, we focused on defect control. Developing thermoelectric materials via solution processing involves numerous challenges. One, mitigating oxidation due to the nanoparticles'high surface to volume ratio.

Reproducibility, due to the complexity of the process. And three, dealing with volatile species to ensure stability. Addressing and understanding these challenges is crucial for enhancing thermal electric materials efficiency for practical applications.

Our research advanced cost-effective solution-processed thermal electric materials, by fine-tuning nanoparticle properties and their organization. We are uncovering the chemistry involved in the whole process, from the nanoparticle synthesis to the final consolidation. And currently, we are focused on how surface species or affect materials microstructure, and hence their performance.

We enhanced thermoelectric performance through the utilizing solution process surface engineered particles, significantly reducing the thermal conductivity by micro structural tuning and the introduction of defects. This approach also is advantageous, because it uses inexpensive precursors, low temperatures, and also, we use water as a solvent. We found that certain molecules absorb at the particle surface and restrict grain growth.

Now, we are trying to rationalize how different surface species affect microstructure and hence transport properties, based on their composition, chemical instability, and bonding nature.