Flexible Thin-film Planar Peltier Microcooler

The present work reports on the fabrication and characterization of a planar Peltier microcooler on flexible substrate. The microcooler was fabricated on flexible Kaptoncopy polyimide sheet, 12 mum thick, using Bi₂Te₃ and Sb₂Te₃ thermoelectric elements, deposited by thermal co-evaporation. The cold area of the device (4 mm²) is cooled using four pairs of thermoelectric elements, connected in series with aluminium/nickel contacts. Optimization of deposition parameters allowed the fabrication of films with power factors of 4.9 times 10^-3 WmiddotK ^-2middotm^-1 and 3.3 times 10^-3 WmiddotK^-2middotm^-1 for Bi₂Te₃ and Sb₂Te₃, respectively. These values are comparable with the best published results for the same material, under various fabrication methods (thermal co-evaporation, sputtering, MOCVD, flash-evaporation or ECD). The performance of the Peltier microcooler was analyzed by infrared image microscopy in still-air and vacuum. The temperature difference between the cold side and the hot side of the device was 4degC