Thin-Film Thermoelectric Modules for Power Generation Using Focused Solar Light

• Published in: Journal of electronic materials 2012-06, Vol.41 (6), p.1713-1719
• Main Authors: Mizoshiri, Mizue, Mikami, Masashi, Ozaki, Kimihiro, Kobayashi, Keizo
• Format: Article
• Language: English
• Subjects: Annealing; Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Cross-disciplinary physics: materials science; rheology; Deposition; Deposition by sputtering; Electric potential; Electric power; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in condensed matter; Electronic transport phenomena in thin films and low-dimensional structures; Electronics; Electronics and Microelectronics; Exact sciences and technology; Generators; Glass; Instrumentation; Magnetron sputtering; Materials Science; Methods of deposition of films and coatings; film growth and epitaxy; Modules; Optical and Electronic Materials; P-n junctions; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solar energy; Solid State Physics; Thermoelectric and thermomagnetic effects; Thermoelectric effects; Thermoelectric, pyroelectric devices, etc; Thermoelectricity; Thin films
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-012-2047-0

We demonstrated the fabrication of thin-film thermoelectric generators and evaluated their generation properties using solar light as a thermal source. Thin-film elements of Bi 0.5 Sb 1.5 Te 3 ( p -type) and Bi 2 Te 2.7 Se 0.3 ( n -type), which were patterned using the lift-off technique, were deposited on glass substrates using radiofrequency magnetron sputtering. After annealing at 300°C, the average Seebeck coefficients of p - and n -type films were 150  μ V/K and −104  μ V/K, respectively, at 50°C to 75°C. A cylindrical lens was used to focus solar light to a line shape onto the hot side of the thin-film thermoelectric module with 15 p – n junctions. The minimum width of line-shaped solar light was 0.8 mm with solar concentration of 12.5 suns. We studied the properties of thermoelectric modules with different-sized p – n junctions on the hot side, and obtained maximum open voltage and power values of 140 mV and 0.7  μ W, respectively, for a module with 0.5-mm p – n junctions. The conversion efficiency was 8.75 × 10 −4 %, which was approximately equal to the value estimated by the finite-element method.