A new material for thin-film low-voltage blue phosphors

— Blue cathodoluminescence (CL) with a spectral peak at 400 nm is reported in tantalum‐incorporated ZnO thin films at low voltages. The CL is visible at 10 V at a current density of 10 μA/cm2. The CL chromaticity coordinates are found to be x = 0.160, y = 0.075. The films have been prepared by depositing a thin tantalum film on rf‐magnetron‐sputtered and annealed ZnO films, followed by another annealing step. The films also exhibit strong photoluminescence, peaking at 383 nm (3.2 eV). The x‐ray‐diffraction analysis shows the presence of a Ta2Zn3O8 phase in these films, which is believed to be responsible for the observed luminescence.