Microlitre scale solution processing for controlled, rapid fabrication of chemically derived graphene thin films

We report a new class of rapid solution processes for fabricating highly uniform chemically derived graphene thin films with control over the thickness on the subnanometre scale. The film deposition directly on various substrates is driven by dragging a meniscus of microlitre graphene oxide (GO) suspension trapped between two plates. The fine tuning of the optoelectronic properties of the graphene thin films is achieved by simply varying the number of depositions, GO concentration, dragging speed, and angle between two plates. This coating technique is simple, inexpensive, and easy to scale for large-area graphene films used as transparent electrodes with a significant reduction of the material consumption.