A high performance flexible and robust printed thermoelectric generator based on hybridized Te nanowires with PEDOT:PSS

In this work, we demonstrate a water-based scalable synthetic method of Te nanowires (NWs) and formulation of hybrid thermoelectric (TE) inks utilizing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), towards the fabrication of high performance and flexible printed thermoelectric generators (TEGs). X-Ray diffraction (XRD) and Raman spectra confirm the high crystallinity of Te NWs nanocrystals with hexagonal lattice. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) illustrated the microstructural features of the produced nanostructures, as well as the monocrystalline nature of the synthesized Te NWs. Hall-effect measurements determined the carrier density and mobility of Te NWs and their hybrid materials. According to the thermoelectric response and best power factor (PF) of the hybrid inks measured in solid-state of pre-fabricated films (max. PF = 102.42 μW/m K2), a flexible TEG has been fabricated with a power output (Pout) of ~ 4.5 µW upon being exposed to ΔT = 100 K. The fabricated TEG demonstrated herein can be produced in a continuous and scalable roll-to-roll (R2R) printing process using i.e. slot die, gravure, etc. printing technologies towards the realization of large scale flexible TEG production and future large scale thermal energy harvesting by printed TEG devices.