Enhanced Thermoelectric Performance of n-Type Bi2Se3 Nanosheets through Sn Doping

Abstract

The cost-effective conversion of low-grade heat into electricity using thermoelectric devices requires developing alternative materials and material processing technologies able to reduce the currently high device manufacturing costs. In this direction, thermoelectric materials that do not rely on rare or toxic elements such as tellurium or lead need to be produced using high-throughput technologies not involving high temperatures and long processes. Bi2Se3 is an obvious possible Te-free alternative to Bi2Te3 for ambient temperature thermoelectric applications, but its performance is still low for practical applications, and additional efforts toward finding proper dopants are required. Here, we report a scalable method to produce Bi2Se3 nanosheets at low synthesis temperatures. We studied the influence of different dopants on the thermoelectric properties of this material. Among the elements tested, we demonstrated that Sn doping resulted in the best performance. Sn incorporation resulted in a significant improvement to the Bi2Se3 Seebeck coefficient and a reduction in the thermal conductivity in the direction of the hot-press axis, resulting in an overall 60% improvement in the thermoelectric figure of merit of Bi2Se3.

Enhanced Polysulfide Conversion with Highly Conductive and Electrocatalytic Iodine‐Doped Bismuth Selenide Nanosheets in Lithium–Sulfur Batteries

“…The highest energy doublet was associated with Bi 3+ within a more electronegative environment, as it could be Bi 2 O 3 , Bi 2 (SeO 3 ) 3 , Bi 2 SeO 2 , or another oxidized form of Bi 2 Se 3 (Bi 4f 7/2 binding energy at 158.5 eV). [45,46] The presence of an oxide component was related to the transportation and handling of the particles in the air. The Bi 4f XPS spectrum of Bi 2 Se 3 displayed the same two doublets, but the one corresponding to Bi within Bi 2 Se 3 was slightly shifted to lower binding energies (Bi 4f 7/2 at 157.3 eV).…”

Synthesis and Properties of Bismuth Selenide Based Nanolaminates for Application in Thermoelectrics

“…The obtained data are in good agreement with the previously reported XPS measurements of 13 nm thin Bi 2 Se 3 nanosheets. [ 24 ] The high‐resolution Te 3d spectrum pointed to the presence of Te in Bi 2 Se 3 (peak located at 572.9 eV corresponding to Te 3d 5/2 , Figure 2c), as well as to the presence of Te in TeO 2 chemical environment (peak located at 576.3 eV). The oxidation of the surface of Bi 2 Se 2.975 Te 0.025 most likely is related to the sample handling and storage in the air.…”

Solution-Processed Inorganic Thermoelectric Materials: Opportunities and Challenges

“…Optical emission spectroscopy (ICP-OES) and mass spectroscopy have the necessary elemental sensitivity but do not provide information on the distribution of measured elements. Therefore, techniques that are sensitive to the atomic environment and the surface should be employed, such as X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy (XPS), which are also sensitive to the oxidation state of the elements and the presence of oxide. , …”

“…Therefore, techniques that are sensitive to the atomic environment and the surface should be employed, such as X-ray absorption spectroscopy, 154 and X-ray photoelectron spectroscopy (XPS), which are also sensitive to the oxidation state of the elements 155 and the presence of oxide. 156,157 Identifying the surface species is crucial to understanding their role during the formation of the solid. 83 First, the assessment of the surface chemistry is often done with Fouriertransform infrared spectroscopy, which can easily indicate if organic ligands are present.…”

“…Therefore, techniques that are sensitive to the atomic environment and the surface should be employed, such as X-ray absorption spectroscopy, 154 and X-ray photoelectron spectroscopy (XPS), which are also sensitive to the oxidation state of the elements 155 and the presence of oxide. 156 , 157 …”