Flexible Thermoelectric Reduced Graphene Oxide/Ag2S/Methyl Cellulose Composite Film Prepared by Screen Printing Process

As an organic−inorganic thermoelectric composite material, a flexible, reduced graphene oxide (rGO)/silver sulfide (Ag2S)/methyl cellulose (MC) film was fabricated by a two-step method. Firstly, a rGO/Ag2S composite powder was prepared by a chemical synthesis method, and then, the rGO/Ag2S/MC composite film was prepared by a combined screen printing and annealing treatment process. The rGO and rGO/Ag2S composite powders were evenly dispersed in the rGO/Ag2S/MC composite films. A power factor of 115 μW m−1 K−2 at 520 K was acquired for the rGO/Ag2S/MC composite film, which is ~958 times higher than the power factor at 360 K (0.12 μW m−1 K−2), mainly due to the significant increase in the electrical conductivity of the composite film from 0.006 S/cm to 210.18 S/cm as the test temperature raised from 360 K to 520 K. The as-prepared rGO/Ag2S/MC composite film has a good flexibility, which shows a huge potential for the application of flexible, wearable electronics.