1. Highly-efficient thermoelectric pn-junction device based on bismuth telluride (Bi2Te3) and molybdenum disulfide (MoS2) thin films fabricated by RF magnetron sputtering technique.
- Author
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Kogo, Gilbert, Lee, Harold, Ibrahim, Adem H., Bo, Xiao, Pradhan, Sangram K., and Bahoura, Messaoud
- Subjects
THERMOELECTRICITY ,BISMUTH telluride ,MOLYBDENUM disulfide ,METALLIC thin films ,NANOFABRICATION ,MAGNETRON sputtering - Abstract
Layered structure bismuth telluride and molybdenum disulfide thin films were successfully deposited on different substrates using radio-frequency magnetron sputtering technique. The structural, morphological, and thermoelectric transport properties of bismuth telluride and molybdenum disulfide thin films have been investigated systematically to fabricate high-efficient thermal energy harvesting thermoelectric device. The magnitude of the Seebeck coefficient of bismuth telluride thin films decreases with increase in film thickness. Bismuth telluride grown at 350 °C for 10 min, which is approximately 120 nm, displays a maximum Seebeck coefficient of −126 μV K
−1 at 435 K. The performance shows strong temperature dependence when the films were deposited at 300 °C, 350 °C, and 400 °C. The power factor increases from 0.91 × 10−3 W/mK2 at 300 K to about 1.4 × 10−3 W/mK2 at 350 K. Molybdenum disulfide films show the positive Seebeck coefficient values and their Seebeck coefficient increases with film thickness. The AFM images of bismuth telluride thin films display a root-mean-square (rms) roughness of 32.3 nm and molybdenum disulfide thin films show an rms roughness of 6.99 nm when both films were deposited at 350 °C. The open-circuit voltage of the pn-junction thermoelectric generator (TEG) device increases with increase in ΔT to about 130 mV at ΔT = 120 °C. We have demonstrated a highly efficient pn-junction TEG device for waste heat recovery applications. [ABSTRACT FROM AUTHOR]- Published
- 2018
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