High-power-density spot cooling using bulk thermoelectrics

We demonstrate a three-dimensional (3D) bulk silicon microcooler, which has the advantages of high cooling power densities and is less dependent on thermoelectric element’s thickness as compared with the same device with one-dimensional (1D) geometry. We measured a maximum cooling of 1.2 °C for a 40×40 μm² area bulk silicon microcooler device, which is equivalent to an estimated cooling power density of 580 W/cm². In this unique geometry, both current and heat spreading in 3D allows the maximum cooling temperature to exceed the conventional 1D thermoelectric model’s theoretical limit 0.5 ZT_c².