Laser Treatment as Sintering Process for Dispenser Printed Bismuth Telluride Based Paste

Abstract

Laser sintering as a thermal post treatment method for dispenser printed p- and n-type bismuth telluride based thermoelectric paste materials was investigated. A high-power fiber laser (600 W, 1064 nm) was used in combination with a scanning system to achieve high processing speed. A Design of Experiment (DoE) approach was used to identify the most relevant processing parameters. Printed layers were laser treated with different process parameters and the achieved sheet resistance, electrical conductivity, and Seebeck coefficient are compared to tube furnace processed reference specimen. For p-type material, electrical conductivity of 22 S/cm was achieved, compared to 15 S/cm in tube furnace process. For n-type material, conductivity achieved by laser process was much lower (7 S/cm) compared to 88 S/cm in furnace process. Also, Seebeck coefficient decreases during laser processing (40–70 µV/K and −110 µV/K) compared to the oven process (251 µV/K and −142 µV/K) for p- and n-type material. DoE did not yet deliver a set of optimum processing parameters, but supports doubts about the applicability of area specific laser energy density as a single parameter to optimize laser sintering process.

Additive Manufacturing of Bulk Thermoelectric Architectures: A Review

“…The same hybrid AM approach was later employed as a post treatment for material extrusion-printed samples by Greifzu et al [90] to fabricate thin films with both n-and p-type Bi 2 Te 3 . Considerably higher laser power and scanning speeds of 80-150 W and 2500-5000 mm/s, respectively, were employed under a regular hatch distance range of 0.3-0.5 mm, which corresponded to energy density ranges of 0.025-0.250 J/mm 2 for the n-type Bi 2 Te 3 and 0.025-0.160 J/mm 2 for the p-type Bi 2 Te 3 .…”

Microstructure of Butt Joint of High-Silicon Steel Made Using CO2 Laser Welding and Inconel 82 Filler

“…Lasers have been widely used in many industrial applications, such as heat treatment, ablation, surface modification, precision cutting, cladding, welding and 3-D printing in recent years, and they demonstrate great potential in many areas of advanced materials processing [1][2][3][4][5][6][7]. With the rapid advancement of laser technology, many lasers have been used in the fabrication of metallic engineering components [8,9].…”

Microstructure Evolution in Plastic Deformed Bismuth Telluride for the Enhancement of Thermoelectric Properties

“…Bismuth-tellurium-based materials are excellent TEGs for near-room temperature (RT) applications and are widely used commercially. Typically, the fabrication of TEG devices involves a series of processes, such as the synthesis of bulk ingots via zone melting, dicing, plating cleaning, and soldering [20][21][22][23]. During device fabrication, expensive material resources are wasted because many scraps are unavoidably produced [24][25][26].…”