Semiconductor glass with superior flexibility and high room temperature thermoelectric performance

Abstract

Most crystalline inorganic materials, except for metals and some layer materials, exhibit bad flexibility because of strong ionic or covalent bonds, while amorphous materials usually display poor electrical properties due to structural disorders. Here, we report the simultaneous realization of extraordinary room temperature flexibility and thermoelectric performance in Ag₂Te_1-<i>x</i> S <i>_x</i> -based materials through amorphization. The coexistence of amorphous main phase and crystallites results in exceptional flexibility and ultralow lattice thermal conductivity. Furthermore, the flexible Ag₂Te_0.6S_0.4 glass exhibits a degenerate semiconductor behavior with a room temperature Hall mobility of ~750 cm² V^-1 s^-1 at a carrier concentration of 8.6 × 10¹⁸ cm^-3, which is at least an order of magnitude higher than other amorphous materials, leading to a thermoelectric power factor also an order of magnitude higher than the best amorphous thermoelectric materials known. The in-plane prototype uni-leg thermoelectric generator made from this material demonstrates its potential for flexible thermoelectric device.