Enhanced field emission from reduced graphene oxide polymer composites.

Results on electron field emission (FE) from reduced graphene oxide (rGO):poly(3-hexylthiophene) (P3HT) composite layers are presented. Three different FE cathodes were tested and compared: rGO layers on (a) n(+)-Si, (b) composite films with different rGO:P3HT ratios, (c) rGO layers on composite films with different rGO:P3HT ratios. Experiments show that there is a critical rGO:P3HT ratio in which the field-emission performance is remarkably improved. Notably, such performance is always superior to that of the optimum rGO/n(+)-Si cathode. On the contrary, it is inferior to that attained upon deposition of a second rGO layer on top of the rGO:P3HT composite showed the best FE performance that showed turn-on field of as low as ~0.9 V/μm and field enhancement factor of ~1900. The contributions of the composite film morphology as well as the role of rGO sheet-substrate interaction on the emission performance are evaluated and discussed.