Thermoelectric (TE) coolers work on the Seebeck effect, where an electrical current is used to drive a heat flux against a temperature gradient. They have applications for active cooling of electronic devices but have low coefficients of performance (COP<1) at high heat fluxes (>10 W/cm2). While the active elements (thermoelectric material) in a TE cooling module lead to cooling, the non-active elements, such as the electrical leads and headers, cause joule heating and decrease the coefficient of performance. A conventional module design uses purely horizontal leads and vertical active elements. In this work, we numerically investigate trapezoidal leads with angled active elements as a method to improve cooler performance for both supperlattice thin film and bulk thermoelectric materials. We show that, for a constant packing fraction, defined as the ratio of active element area to the couple base area, trapezoidal leads decrease electrical losses but also increase thermal resistance. We also demonstrate that trapezoidal leads can be used to increase the packing fraction to values greater than one, leading to a two times increase in heat pumping capacity. Thus the present work provides a pathway to improve the efficiency of the state-of-the-art thermoelectric coolers by > 30% at a two times higher heat flux.

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