A hierarchical design for thermoelectric hybrid materials: Bi2Te3 particles covered by partial Au skins enhance thermoelectric performance in sticky thermoelectric materials

Abstract

Sticky thermoelectric (TE) materials have been inversely designed to enable the mass production of flexible TE sheets through lamination or roll-to-roll processes without using electrically conductive adhesives. They have also been demonstrated as inorganic/organic hybrid materials consisting of TE inorganic particles and low-volatilizable organic solvents to exhibit Seebeck coefficients based on the TE particles and low thermal conductivities based on the organic matrix. To achieve energy harvesting of 250 µW for driving various electric devices using voltage boosters, herein, we employ p- and n-type Bi2Te3 particles due to their high Seebeck coefficients, and cover the Bi2Te3 bodies with Au skins because the interfacial electrical resistance depends on the electrical resistance of opposing substances at the interface. After controlling the plating amount to cover the Bi2Te3 particles with Au skins, we achieve a TE power generation two orders of magnitude greater than the previous study, i.e., 255 µW on a hot plate of 110 °C with a 6 × 6 module. Overall, with input from other organic devices, like organic light-emitting diodes and dye-sensitized solar cells, this study presents a hierarchical design for TE hybrid materials that suppresses the thermal conduction by hybridizing TE particles with the organic matrix at the microscale. This reduces the electrical resistance by modifying the interfaces of the TE particles at the nanoscale and optimizes the Seebeck coefficient of TE particles at the atomic scale. To compete with solid-state TE modules with regards to power generation capacity, the hierarchical design towards a possible further two orders of magnitude improvement is also discussed.

Keynote Review of Latest Advances in Thermoelectric Generation Materials, Devices, and Technologies 2022

“…Additionally, the temperature difference which can be obtained from wearable application is relatively small, so the output power is small, and highest performance from the materials themselves is desirable. Another issue is that it has been pointed out that many of the polymer-based modules ultimately use expensive metal (e.g., silver, gold) pastes as contacts, so are actually not inexpensive and different approaches may also be necessary to consider [105,106]. In the case of Ag 2 S or Ag 2 Se-based materials, they have relatively high performance, however, the materials with silver as the major component are quite costly, and inexpensive module fabrication methods also need to be developed.…”

Energy harvesting through thermoelectrics: topological designs and materials jetting technology

“…Besides harvesting waste heat from factories, heat from photovoltaic cells [4] and high-power light-emitting diodes [5] have also shown potential for energy conversion through TE devices. On a smaller scale, a small temperature difference between the human body heat (waste heat energy) and the environment is also able to generate usable energy to power wearable electronic devices [6][7][8][9][10][11][12] .…”