Microstructurally Tailored Thin β-Ag2 Se Films towards Commercial Flexible Thermoelectrics.

Aiming to overcome both the structural and commercial limitations of flexible thermoelectric power generators (F-TEGs), we designed an efficient room-temperature aqueous selenization reaction that could be completed in air within less than 1 min, to directly fabricate thin β-Ag2 Se films consisting of perfectly crystalline and large columnar grains with both in-plane randomness and out-of-plane [201] preferred orientation. A high power factor (PF) of 2590 ± 414 μW m-1 K-2 and a figure-of-merit (zT) of 1.2 ± 0.42 were obtained from the sample with a thickness of ∼1 μm. The maximum output power density (MOPD) of the best 4-leg TEG sample reached up to 27.6 ± 1.95 and 124 ± 8.78 W·m-2 at room temperature with 30 K and 60 K temperature differences, respectively, which may be used in future flexible TE devices. This article is protected by copyright. All rights reserved.