Scalable, Low-Cost Ink-Based Processing of High-Performance Silver Selenide Thermoelectrics

Abstract

The growing global energy demand and its accelerating contribution to climate change emphasize the urgent need for sustainable energy conversion/harvesting technologies. Thermoelectric (TE) devices offer a compelling route to directly convert waste heat into electricity and enable solid-state cooling without moving parts or harmful refrigerants. Achieving their full potential requires not only higher TE performance (zT) but also scalable, low-cost manufacturing processes. Here, we introduce a transformative ink-based processing approach for the scalable manufacturing of high-performance silver selenide-based TE materials and devices. Using a simple, high-throughput ink-mixing and blade coating strategy, our Ag₂Se-based materials under the optimized composition and processing conditions yield an ultrahigh power factor of 2.8 mW m⁻¹ K⁻², over 100% higher than baseline samples and a reproducible figure of merit zT of 1. A 3D cross-plane thermoelectric generator (TEG) achieves a very competitive power density of 84.3 mW cm⁻² at a 90 °C temperature difference between the hot and cold sides of the device, which is among the highest reported for silver selenide-based devices to date. This facile, scalable ink-based printing method establishes a practical pathway toward industrial-scale manufacturing and widespread adoption of thermoelectric devices, advancing sustainable energy technologies.