A Rapid Methodology to Obtain Silver Selenide thin Films with Highly Enhanced Thermoelectric Performance

Metal chalcogenides have been extensively studied for thermoelectric applications. Among other metal chalcogenides, silver selenide (Ag₂Se) is considered one of the most promising n-type semiconducting materials for thermoelectric applications due to its low band gap value, Seebeck coefficient, and superior power factor (PF) rendered at room temperature. However, one of the main drawbacks of using Ag₂Se as a thermoelectric material on a large scale is the time-consuming physical methods to obtain them, and the need for high vacuum synthesis conditions as well as high-cost. On the contrary, the electrodeposition route offers a fast, low-cost, reliable, eco-friendly, and reproducible synthesis methodology to obtain β-Ag₂Se thin films, avoiding the use of high vacuum, which is especially important for scaling up to industrial processing levels. In this study, a facile and rapid strategy is reported to obtain β-Ag₂Se thin films with controlled thickness using an electrodeposition technique. As-electrodeposited β-Ag₂Se film with a thickness of 740 nm delivered a PF = 5.59 µW cm⁻¹ K², while an 880 nm β-Ag₂Se film annealed at 210 °C exhibits a higher PF = 11.69 µW cm⁻¹ K². The results demonstrate a rapid preparation of high purity β-Ag₂Se thin film with superior thermoelectric performance, provides potential opportunities in the development of efficient thermoelectric devices.