A closer look - what is going on?
The physics in a nutshell
The new solid state heat pump works with a combination of a physical process that absorbs heat to create free carriers within a pn-junction structure and a second process that avoids the release of the heat on the contacts.Because the heat energy is converted in the inside and not released at the contacts (indicated as contact region below), thin (order of 100 µm for standalone devices) and very thin (order of 3-4 µm) devices are possible to be built and operated.
In comparison, the other available solid state process is based on the Peltier effect used in thermoelectric or Peltier modules, which absorbs heat on one side and release it (and even more) again at the other side of the device. This is the reason why thin Peltier devices are not feasible without extended thermal engineering, which results mostly in the necessity of large heat sinks - thus restricting the miniaturisation possibilities. Surface cooling is thus very hard with Peltier effect devices, embedded cooling practically not possible.
All other heat pump processes are based on the transport of liquid and/or gaseous media and thus are also limited in the miniaturization. Cooling of mobile devices or embedded cooling within electronic devices is not practicable.