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There has been a growing interest in solution-phase routes to thermoelectric materials due to the decreased costs and novel device architectures that these methods enable. Many excellent thermoelectric materials are metal chalcogenide semiconductors and the ability to create soluble metal chalcogenide semiconductor precursors using thiol–amine solvent mixtures was recently demonstrated by others. In this paper, we report the first thermoelectric property measurements on metal chalcogenide thin films made in this manner. We create Cu 2−x Se y S 1−y and Ag-doped Cu 2−x Se y S 1−y thin films and study the interrelationship between their composition and room temperature thermoelectric properties. We find that the precursor annealing temperature affects the metal : chalcogen ratio, and leads to charge carrier concentration changes that affect the Seebeck coefficient and electrical conductivity. Increasing the Se : S ratio increases electrical conductivity and decreases the Seebeck coefficient. We also find that incorporating Ag into the Cu 2−x Se y S 1−y film leads to appreciable improvements in thermoelectric performance by increasing the Seebeck coefficient and decreasing thermal conductivity. Overall, we find that the room temperature thermoelectric properties of these solution-processed materials are comparable to measurements on Cu 2−x Se alloys made via conventional thermoelectric material processing methods. Achieving parity between solution-phase processing and conventional processing is an important milestone and demonstrates the promise of this binary solvent approach as a solution-phase route to thermoelectric materials.
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This content will become publicly available on August 1, 2027
3D‐Printed Dual‐Doped Ag 2 Se‐Based Thermoelectric Films With Enhanced Thermal Stability
ABSTRACT While silver selenide (Ag2Se) is considered a promisingn‐type thermoelectric material, the low throughput of conventional solid‐state processing for selenide‐based systems highlights the need for scalable solution‐based alternatives. However, most solution‐processing approaches require thermal annealing to form high‐quality films, whereas Ag2Se exhibits limited thermal stability (<350°C), posing a nontrivial issue for processing. To address this, we systematically investigate the incorporation of a controlled dual dopant (Sb‐Se) into Ag2Se through a compositionally tuned nano‐ink. Flexible SbxAgSe0.5+yfilms were fabricated using the direct ink writing (DIW) approach, and the doped films demonstrated enhanced thermal stability. The effect of dopants on microstructure was further studied using neutron diffraction at the VULCAN instrument and elemental analysis using SEM‐EDS. Results demonstrated that elemental doping of Sb and Se leads to stable/enhanced Seebeck coefficients after thermal exposure, in contrast to undoped Ag2Se films with decreased Seebeck due to thermal degradation, where the thermal behavior and possible degradation pathways are evaluated at 200, 400, and 600°C. A wearable thermoelectric generator (TEG) demonstrated a peak power density of ∼60 µW cm−2at 30°C temperature difference. Overall, this study suggests the possibility of printing‐based Ag2Se thermoelectric devices with high‐temperature processability for waste‐heat harvesting and harsh electronic applications.
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- Award ID(s):
- 2418915
- PAR ID:
- 10703009
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Materials Technologies
- ISSN:
- 2365-709X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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