Effect of Pulse Frequency on Structural and Thermoelectric Properties of Bismuth Telluride Thin Films by Electrodeposition

Abstract

Effects of current pulse frequency and duty ratio [off-time/(on-time + off-time)] on thermoelectric properties of bismuth telluride (Bi2Te3) thin films were investigated. The crystal structure of the Bi2Te3 thin films was strongly affected by the duty ratio rather than the current pulse frequency. In particular, the Bi2Te3 thin films were highly oriented along (1 1 0) direction with smooth surface at the high current pulse frequency (5000 Hz) and the high duty ratio (80%). Overall, the electrical conductivities of the Bi2Te3 thin films with current pulse frequency of 5000 Hz were larger than that the thin films with 1000 Hz, whereas the Seebeck coefficients were mostly the same between the both frequencies. As a result, the highest power factor (1.1 μW/(cm·K2)) was observed at the Bi2Te3 thin films with a current pulse frequency of 5000 Hz and a duty ratio of 60%.

Combination of Electrodeposition and Transfer Processes for Flexible Thin-Film Thermoelectric Generators

“…The Bi 2 Te 3 and Sb 2 Te 3 thin films were prepared by potentiostatic electrodeposition using a standard three-electrode cell. The basic setup used for the electrodeposition of both thin films has been described in our previous reports [19,37,38]. A stainless-steel substrate with a thickness of 80 µm was chosen as the working electrode (electrode area: 1.5 cm 2 ) because of its excellent corrosion resistance.…”

Power Generation in Slope-Type Thin-Film Thermoelectric Generators by the Simple Contact of a Heat Source

“…Prior to the fabrication of slope-type thin-film thermoelectric generators, we prepared n-type Bi 2 Te 3 and p-type Sb 2 Te 3 thin films using potentiostatic electrodeposition and a standard three-electrode cell; we then measured their thermoelectric properties. The basic setup used for the electrodeposition of both thin films has been described in our previous reports [14,39,40]. A stainless-steel substrate with a thickness of 80 µm was used as the working electrode (electrode area: 1.5 cm 2 ), and a platinum-coated titanium mesh on a titanium plate was used as the counter electrode (combined area electrode of the mesh and plate: 1.5 cm 2 ).…”

Fan‐Shaped Flexible Radioisotope Thermoelectric Generators Based on BixTeyand BixSb2‐xTeyFabricated Through Electrochemical Deposition

“…Current methods for synthesizing inorganic TE thin-film materials include high-temperature sintering, [17] molecular beam epitaxy, [18,19] organometallic chemical vapor deposition, [20] flash evaporation method, [21] and electrodeposition. [22] Electrodeposition offers advantages such as selective deposition, high deposition rate, and low temperature and pressure operating environments compared with other methods. Electrodeposition can control the crystallinity, composition, and morphology of TE thin-film materials by adjusting deposition conditions and electrolyte composition.…”

“…Current methods for synthesizing inorganic TE thin‐film materials include high‐temperature sintering, molecular beam epitaxy, organometallic chemical vapor deposition, flash evaporation method, and electrodeposition . Electrodeposition offers advantages such as selective deposition, high deposition rate, and low temperature and pressure operating environments compared with other methods.…”