Printing of colored pattern using atomic layer deposition

A printer head assembly comprising:

• a printer head comprising a body formed with:
• a first injection chamber for injecting first gas onto a substrate, and
• a second injection chamber surrounding the first injection chamber, the second injection chamber configured to inject second gas onto the substrate, the second gas reacting or replacing molecules of the first gas adsorbed on the substrate to form a layer of material on the substrate;
• and
• a conduit connected to the printer head to provide the first gas and the second gas to the printer head.

A method of forming a pattern on a substrate, comprising:

• injecting source precursor onto a surface of a substrate via a printer head;
• injecting reactant precursor onto the surface via the printer head;
• moving the printer head along a path on a substrate while controlling at least a parameter associated with a thickness of layer deposited on the substrate by reaction or replacement of molecules of the source precursor with molecules of the reactant precursor on the surface;
• and
• discharging excess source precursor and reactant precursor from the surface of the substrate via the printer head.