Fabrication of a unipolar Peltier device using a pair of N-type thermoelectric materials

Abstract

We proposed and fabricated an NN-type Peltier device composed of two small N-type Bi2Se0.37Te2.36 thermoelectric bulk materials. This structure includes an additional electric wire between the two N-type bulks. We introduce an application of the NN-type Peltier device as a stage on which a temperature difference can be induced by altering the current, targeting a rapid amplification system for deoxyribonucleic acid (a thermal cycler for the polymerase chain reaction). The currents in the two circuits differ from each other. The current dependence of the stage temperature of the NN-type Peltier device was investigated and the temperature difference on the stage was 21.4°C at a current of 24A. To analyze the device performance, the heat balance for the Peltier device composed of two N-type bulks was obtained by considering the effects of the electric resistance and thermal conductance of the central electric wire between the two N-type materials. The Seebeck coefficient, total resistance, total thermal conductance, and heat absorption were obtained by fitting to be −4.24×10−4V/K, 2.55×10−4Ω, 0.159W/K, and 1.13W, respectively, which were in good agreement with those estimated using literature values. Moreover, we fabricated an NN-type thermoelectric power device with a temperature difference of 70K, an open voltage of 16V, and a maximum power of 8mW at a current of 0.9A.