Flexible Carbon Nanotube-Epitaxially Grown Nanocrystals for Micro-Thermoelectric Modules.

Flexible thermoelectric materials have attracted increasing interest because of their potential use in thermal energy harvesting and high-spatial-resolution thermal management. However, a high-performance flexible micro-thermoelectric device (TED) compatible with the microelectronics fabrication process has not yet been developed. Here we report a universal epitaxial growth strategy guided by one-dimensional van der Waals-coupling, to fabricate freestanding and flexible hybrids comprised of single-wall carbon nanotubes and ordered (Bi,Sb) 2 Te 3 nanocrystals. High power factors ranging from ∼1680 to ∼1020 μW m -1 K -2 in the temperature range of 300 K to 480 K, combined with a low thermal conductivity yield a high average figure of merit of ∼0.81. The fabricated flexible micro-TED module consisting of two p-n couples of freestanding thermoelectric hybrids has an unprecedented open circuit voltage of ∼22.7 mV and a power density of ∼0.36 W cm -2 under a ∼30 K temperature difference, and a net cooling temperature of ∼22.4 K and a heat absorption density of ∼92.5 W cm -2 . This article is protected by copyright. All rights reserved.