Thermoelectric properties of n-type Bi₂Te_2.7Se _0.3 and p-type Bi_0.5Sb_1.5Te₃ films for micro-cooler applications

Bi₂Te₃ and its solid solution remain the state-of-the-art thermoelectric materials for refrigeration applications in microelectronics industry, such as dissipating the heat generated by various devices. The fabrication method and associated processing parameters are to be optimised to get desirable composition exhibiting better electrical and thermal transport properties. Carrier concentration and mobility are found to be crucial in achieving high thermoelectric cooling efficiency and energy conversion. In this paper, we present the fabrication and analysis of thermoelectric thin films deposited by RF-magnetron sputtering from n-type Bi₂Te _2.7Se_0.3 and ptype Bi_0.5Sb_1.5Te ₃ targets on a silicon substrate. X-ray diffraction, Scanning electron microscopy combined with energy dispersive spectrometry, electrical resistivity, Seebeck coefficient and thermal diffusivity measurements were used for the thermoelectric thin films characterization. We studied the effect of sputtering process parameters, on the structural, electrical and thermal transport characteristics of films. The observed results demonstrate both n-and p-type doped Bi₂Te₃ films exhibit desirable properties and could be potential candidates for thermoelectric micro-cooler applications.