MnTe Rising: A Modern Era of Thermoelectric and Altermagnetic Materials

Manganese telluride (MnTe) has emerged as a promising eco-friendly thermoelectric (TE) material, combining Earth abundance, structural robustness, and favorable electronic properties. While its intrinsic wide band gap and high Seebeck coefficient (∼600 μV K–1) offer considerable promise, performance has traditionally been limited by low carrier concentration and mobility. This Perspective highlights recent advances that have overcome these limitations through specific doping strategies, valence band engineering, and multiscale nanostructuring. These improvements have led to significantly enhanced figures of merit (zT ≈ 1.6 at 873 K). In parallel, entropy-driven alloying has enabled the stabilization of high-symmetry cubic MnTe phases, improving electrical transport and reducing lattice thermal conductivity. Beyond thermoelectrics, MnTe has also emerged as an altermagnet candidate, an unconventional magnetic phase characterized by symmetry-protected spin-split electronic bands without net magnetization. This unique property introduces asymmetric density of states, offering fresh pathways for boosting thermoelectric efficiency for mass-market applications. This Perspective consolidates recent advances in the structural, electrical, and thermal engineering of MnTe. The interplay of advanced thermoelectric behavior and emergent altermagnetism positions MnTe as a multifunctional platform for next-generation energy and spintronic devices.