Facile fabrication of Cu2O nanowire networks with large Seebeck coefficient for application in flexible thermoelectrics

Abstract

The development of thermoelectrical nanowires and nanowire networks is crucial for application in self-powered electronics and flexible heat-to-power conversion devices. While Cu2O is a perspective p-type thermoelectric material, its research is mostly focused on the investigation of the properties of thin films or rigid cement composites with Cu2O powder fillers. In this work, Cu2O nanowire networks were fabricated by a simple technique and their thermoelectrical properties were investigated for the first time. Cu2O nanowire networks were obtained by annealing prefabricated CuO nanowire networks in an inert atmosphere at low pressure of 0.2 Torr. After annealing, nanowire networks showed a complete transition of CuO phase to Cu2O. Seebeck coefficient of Cu2O nanowire networks reached 2000 μV K−1. The estimated power factor of the Cu2O networks was found to be comparable with the Seebeck coefficient values of the state-of-the-art Cu2O thin films. The demonstrated in this work simple low-cost method for the fabrication of Cu2O nanowire networks illustrates the potential of this material for further applications in flexible thermoelectric devices.