Researchers have fabricated a self-assembled, carbon-based nanofilm where the charge state (ie, electronically neutral or positive) can be controlled at the level of individual molecules. Molecular self-assembly on a metal results in a high-density, 2D, organic quantum-dot array with electric-field-controllable charge state, with the organic molecules used as ‘nano-sized building blocks’ in fabrication of functional nanomaterials. Achieved densities are an order of magnitude larger than conventional inorganic systems.