Formation and field emission property of single-crystalline Zn microtip arrays by anodization

A highly ordered array of single-crystalline Zn microtips is obtained after anodizing of Zn foil in NH4Cl/H2O2 solution, and the formation mechanism and field emission property of such Zn microtips have been described. Sixfold single-crystalline Zn microtips are obtained by selective anisotropic etching of crystallographic planes with different dissolution rates. From the results of TEM analysis, the single-crystalline Zn microtips, formed on the Zn foil after anodic dissolution treatment, are enclosed by {11¯00} and are preferentially oriented along the c-axis. Besides, the improvement of turn-on field from 33.9 to 20.0 V/μm is achieved with thin surface ZnO after annealing treatment.