Korean researchers have succeeded in creating a thermoelectric device that converts heat energy directly into electrical energy with so-called ‘dream material’ graphene.


The Korea Institute of Science and Technology (KIST) announced on March 27 that the Dr. Son Jong-gon of photoelectron hybrid research center team had a ‘graphene nano-mesh’ structure with a regular hole at 10 nm (nanometer, one billionth of a meter) and has developed a thermoelectric device with thermoelectric performance.

Graphene is a thin plate-like material consisting of one layer of carbon atoms and has excellent electrical properties. The performance of existing thermoelectric materials is known to be inversely proportional to the thermal conductivity and electrical conductivity, which is indicative of the power change with temperature, and to the thermal conductivity. In other words, the electrical conductivity must be high and the thermal conductivity must be low to be thermoelectric.

However, unlike conventional materials, graphene has a high electric conductivity and thermal conductivity, and a relatively low thermoelectric coefficient, which hinders the improvement of thermoelectric performance.

The researchers have applied ``nanolithography`` technology to create a nano-sized pattern that has been proposed at the theoretical level, and have made large-area nano patterns of less than 10 nm on graphene. This graphene nano-mesh structure drastically reduced the thermal conductivity while maintaining electrical conductivity. The researchers also found that this phenomenon is due to selective scattering of the transport path of ‘phonon’, which is a virtual particle that transfers heat from graphene with no loss of heat transferring electrons.

Dr. Son said, ‘Thermoelectric properties control technology through graphene nano-pattern will present a new paradigm for the development of curved thermoelectric devices. The research on nano-structured low-dimensional materials and flexible thermoelectric material research and development of wearable is expected to be a solution.’ The research results were published in the online edition of Nano Energy, an international journal for energy.

By Nam Do Yeong namdo0@


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