Controlled Growth of Bronze Telluride for Scalable Thermoelectric Energy Harvesting

Abstract: With the growing demand for sustainable and decentralized energy solutions, thermoelectric energy harvesting has emerged as a promising technology for directly converting waste heat into electricity through solid state, environmentally friendly means. Among copper chalcogenides, Cu2Te is a notable p-type material due to its degenerate semiconducting nature and low thermal conductivity. In this study, we present a sustainable synthesis strategy for Sn-doped Cu2Te referred to as bronze telluride (BT) via a chemical vapor deposition (CVD) assisted tellurization process using pre-alloyed Cu Sn (bronze) powder. The resulting BT exhibited an enhanced thermoelectric figure of merit (ZT) of 1 at 500 K. To assess practical applicability, BT was integrated with n type galena (PbS) in a cascaded p n thermoelectric module, which generated 2.8 mV across a temperature gradient of 35 K, demonstrating its potential for medium- to high-temperature waste heat recovery. Furthermore, thermodynamic calculations and density functional theory (DFT) simulations provided insights into the formation mechanism of Cu2Te and the thermoelectric behaviour of BT. This work introduces an efficient, scalable, and environmentally responsible pathway for developing copper-based thermoelectric materials using industrially relevant precursors.