A direct conversion between electrical and thermal energy can be

accomplished using the thermoelectric (TE) cogenerators. Among

advantages of the TE convertors is the absence of mechanical

components and undesirable chemical residue. In particular, a TE

device contains no moving parts nor does it emit undesirable

chemicals, like chlorofluorocarbons, etc. (DiSalvo 1999, Bell 2008).

Implementing a TE device, the heat can be converted to electricity

and vice versa. The TE coolers are consuming the electrical power

which is supplied to a TE device and which causes the Peltier effect.

Depending on the sign of electric current, the Peltier effect results

either in cooling or in the heating of attached objects. A reciprocal

phenomenon is the Seebeck effect, which can be implemented for

converting the heat into usable electrical power. A serious setback

on the path of a wide implementation of the TE devices is their low

efficiency. Typical efficiencies of the most available TE cogenerators

are far below than can be achieved using many other approaches,

for example, a traditional internal combustion engine. It strongly

motivates the searching of systems, mechanisms, and materials

whichmight considerably improve the TE. A basic ingredient of such

activity is a better understanding of fundamental issues related to

the heat transport and the TE phenomena on the nanoscale (Dubi

and Di Ventra 2011).