Flexible thermoelectric Cu–Se nanowire/methyl cellulose composite films prepared via screen printing technology

Cu–Se nanowires (NWs) have been successfully synthesized by a wet chemical method and then flexible Cu–Se NW/methyl cellulose (MC) composite films have been prepared via a screen printing technology. The thermoelectric properties of the composite films were enhanced by a cold-pressing combining annealing treatment. A power factor of 121.87 μWm−1K−2 has been achieved for the Cu–Se NW/MC composite films at 380 K. A flexible thermoelectric generator (f-TEG) assembled by 4-leg of the as-prepared composite films can generate an output voltage of 0.83 mV and a maximum output power of 6.71 nW at a ΔT = 9.5 K. After being bent for 500 cycles, the resistance change ratio of the f-TEG along the strip length direction was only 3.69%, indicating that the f-TEG has a favorable stability. The screen printing process has many advantages, such as low cost, large-scale production, easy for operation, and therefore, it has a great potential for fabrication of flexible inorganic-organic thermoelectric composite films.