Enhanced Thermoelectric Performance of c-Axis-Oriented Epitaxial Ba-Doped BiCuSeO Thin Films

Abstract

We reported the epitaxial growth of c-axis-oriented Bi1−xBaxCuSeO (0 ≤ x ≤ 10%) thin films and investigated the effect of Ba doping on the structure, valence state of elements, and thermoelectric properties of the films. X-ray photoelectron spectroscopy analysis reveal that Bi3+ is partially reduced to the lower valence state after Ba doping, while Cu and Se ions still exist as + 1 and − 2 valence state, respectively. As the Ba doping content increases, both resistivity and Seebeck coefficient decrease because of the increased hole carrier concentration. A large power factor, as high as 1.24 mWm−1 K−2 at 673 K, has been achieved in the 7.5% Ba-doped BiCuSeO thin film, which is 1.5 times higher than those reported for the corresponding bulk samples. Considering that the nanoscale-thick Ba-doped films should have a very low thermal conductivity, high ZT can be expected in the films.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2752-6) contains supplementary material, which is available to authorized users.

Enhanced Thermoelectric and Mechanical Properties of BaO-Doped BiCuSeOδ Ceramics

“…As shown in Figure b, with increasing the BaO doping amount from 0 to 0.175, the XRD peak for the BiCuSeO δ ceramic block is slightly shifted from 30.23 to 29.87°. This result indicates that the lattice constant is increased because Ba 2+ (1.42 Å) with a larger ionic radius replaces Bi 3+ (1.03 Å). , BiCuSeO δ is made up of (Cu 2 Se 2 ) 2– conductive layers and (Bi 2 O 2 ) 2+ insulating layers stacked alternatively along the c axis, and these layers are modified as [(Bi 1– x Ba x ) 2 O 2 ] (2–2 x )+ and [Cu 2 Se 2 ] (2–2 x )– due to substitution, respectively. , However, compared with the Bi 0.825 Ba 0.175 CuSeO δ sample, the diffraction peaks for the Bi 0.8 Ba 0.2 CuSeO δ sample shift to a higher angle, which is ascribed to the solid solubility limit of Ba in the BiCuSeO δ matrix. When the doping content exceeds 0.175, the excess BaO reacts with Se to form the BaSeO 3 phase.…”

Development of an electrochemical sensor based on a barium-doped copper oxide anchored carbon black modified glassy carbon electrode for the detection of Metol

“…Hence, this is also an evidence for the successful formation of Ba-CuO@CB. [28][29][30] FTIR analysis was utilized to demonstrate the functional groups of the prepared nanomaterials, as shown in Fig. 1B.…”