Large external ΔT and cooling power densities in thin-film Bi2Te3-superlattice thermoelectric cooling devices

Experimental I-V-Tc-ΔT data of thin-film superlattice thermoelectric modules is used to determine the internal ΔT, cross-plane Seebeck coefficient, effective thermal interface resistance, device ZT, and Qmax. We demonstrate 55K of external cooling at 300K (Tcmin=244.8K), with an estimated heat pumping capacity of 128W∕cm2. The average ZT300 for the best superlattice devices is 0.75, compared to 0.66 for a bulk BixSb2−xTe3∕Bi2SexTe3−x device. Our model indicates a significantly higher internal ΔT occurs across the active thermoelectric element, which was verified using buried thermocouples.