A featured “vapor transportation” assembly technique was developed to attain layer-by-layer stacking
continuous graphene oxide (GO) films on both flat and concavo-concave surfaces. Few-layer (layer
number < 10) GO sheets were “evaporated” (carried by water vapor) from the water-dispersed GO
suspension and smoothly/uniformly tiled on the substrate surface. We have found evidence of the
influence of the deposition time and substrate–liquid separation on the film thickness. A model was
proposed for interpreting the assembly process. It was found that a current conditioning would induce a
reduction of the GO surface and form an Ohmic contact between the GO–metal interfaces.
Accordingly, an actively modulated GO cold cathode was fabricated by locally depositing continuous GO
sheets on the drain electrode of a metal-oxide-semiconductor field effect transistor (MOSFET). The field
emission current of the GO cathode can be precisely controlled by the MOSFET gate voltage (VGS). A
current modulation range from 1 1010 A to 6.9 106 A (4 orders of magnitude) was achieved by
tuning the VGS from 0.812 V to 1.728 V. Due to the self-acting positive feedback of the MOSFET, the
emission current fluctuation was dramatically reduced from 57.4% (non-control) to 3.4% (controlled).
Furthermore, the integrated GO cathode was employed for a lab-prototype display pixel application
demonstrating the active modulation of the phosphor luminance, i.e. from 0.01 cd m2 to 34.18 cd m2.