Field emitter as a source of electrons and method for making are provided. The emitter is formed by growth of a nitride compound of a group III element or alloys of group III elements on a substrate having a lattice mismatch with the thin film. The lattice mismatch causes columnar growth in the film. The micro columns have tips, thus forming an array of crystalline microtips of the low work function nitride material. The nitride compound is doped during growth. Gallium nitride grown on (111) silicon and doped with silicon produces a surface having low threshold electric field for emission and high current per unit area.