Nanoscale Organic Thermoelectric Materials: Measurement, Theoretical Models, and Optimization Strategies

Abstract

The demands for waste heat energy recovery from industrial production, solar energy, and electronic devices have resulted in increasing attention being focused on thermoelectric materials. Over the past two decades, significant progress is achieved in inorganic thermoelectric materials. In addition, with the proliferation of wireless mobile devices, economical, efficient, lightweight, and bio‐friendly organic thermoelectric (OTE) materials have gradually become promising candidates for thermoelectric devices used in room‐temperature environments. With the development of experimental measurement techniques, the manufacturing for nanoscale thermoelectric devices has become possible. A large number of studies have demonstrated the excellent performance of nanoscale thermoelectric devices, and further improvement of their thermoelectric conversion efficiency is expected to have a significant impact on global energy consumption. Here, the development of experimental measurement methods, theoretical models, and performance modulation for nanoscale OTE materials are summarized. Suggestions and prospects for the future development of these devices are also provided.

Suppression of coherent thermal transport in quasiperiodic graphene-hBN superlattice ribbons

“…In those studies, the thermal conductivity of the superlattice is always lower than the one of the individual pristine materials. Increasing the scattering of coherent phonons or preventing their formation is an efficient mechanism to further decrease the lattice thermal conductivity of superlattices, and enable their application in thermal rectification and thermoelectric devices [29,30,31,32,33]. Nonetheless, deviations from periodicity can originate even more complex phenomena and unusual physical effects.…”

Significant enhancement of the thermoelectric properties of CaP3 through reducing the dimensionality

“…Normally, low κ and/or large power factor S 2 σ are required for designing highly efficient TE devices 6 . However, optimizing simultaneously these transport parameters is an arduous process due to the complex competition among them, which greatly limits the TE performance of materials 7 . In the past few years, in order to regulate and control these complex parameters, band structure engineering 8,9 and quantum confinement effect 10 are devoted to optimize electric transport coefficients, while other effects are presented to reduce κ l through phononic crystal patterning 11,12 or dimensionality reduction 13 .…”

Efficient strain modulation of 2D materials via polymer encapsulation

“…he two-dimensional (2D) materials have attracted considerable attention in recent years, owing to their unique electrical, optical, and mechanical properties at the single atomic thickness [1][2][3][4][5][6][7][8] . From mechanical point of view, 2D materials could withstand deformations over 10% before rupture, which is over one order of magnitude higher than that of typical bulk semiconductors with a break value typically <1% (refs.…”