• Magalhaes, Vh
• Silva, Jpb
• Brito, Fp
• Silva, Mf
• Vieira, Emf
• Pires, Al
• Pereira, Am
• Goncalves, Lm
• Grilo, J.

Abstract

A flexible and ultralight planar thermoelectric generator based on 15 thermocouples composed of n-type bismuth telluride (Bi2Te3) and p-type antimony telluride (Sb2Te3) legs (each with 400 nm thick) connected in series, on 25 mu m thick Kapton substrate, was fabricated with impressive power factor values of 2.7 and 0.8 mW K-2 m(-1) (at 298 K) for Bi2Te3 and Sb2Te3 films, respectively. The p-n junction thermoelectric device can generate a maximum open-circuit voltage and output power of 210 mV and 0.7 mu W (3.3 mW cm(-2)), respectively, for a temperature difference of 35 K, which is higher than the one observed for a conventional thermoelectric device with metallic contacts for p-n junctions. The results were combined with numerical simulations, showing a good match between the experimental and the numerical results. The current density versus voltage (J-V) characteristics of the fabricated p-n junctions revealed a diode behavior with a turn-on voltage of approximate to 0.3 V and an impressive rectifying ratio (I+IV/I-IV ) of approximate to 2 x 10(4).

Topics

• density
• impedance spectroscopy
• simulation
• current density
• Bismuth
• Antimony