Thermoelectric transport through coupled double quantum dots

A thermoelectric device is a solid-state heat engine that operates using the thermoelectric effect, which is the principle of direct conversion of heat energy to electric energy. Today the poor efficiency and relatively high production cost of thermoelectric devices heavily limits their applications. Most thermoelectric devices are built up of semiconductor thermocouples, which consist of an n-dope and a p-doped semiconductor. These are connected in series electrically but thermally in parallel. One way of increasing the efficiency is to replace the bulk structure of the thermocouple with a quantum dot structure. In a quantum dot thermocouple it is instead two quantum dots electrically connected in series but thermally connected in parallel. However, having two quantum dots closely spaced to each other causes electrons in the two quantum dots to interact. This report theoretically investigates how this coupling affects the performance of a quantum dot thermocouple, more specifically how it affects the maximum output power. It is shown that the output power of the quantum dot decreases below the output power of a single quantum dot for strong couplings. (Less)