Optical Response of Epitaxial ZnO Films Grown by Atomic Layer Deposition and Coimplanted with Dy and Yb

In this study, structural and optical properties of ZnO:Dy, ZnO:Yb, and ZnO:(Dy,Yb) films are investigated. Epitaxial ZnO films are grown by atomic layer deposition at 300 degrees C and implanted with Yb and Dy ions to the fluence of 5 x 10(14) cm(-2). The effects of Dy and Yb implantation, Dy/Yb coimplantation, and postgrowth annealing are studied by channeling Rutherford backscattering spectrometry (RBS/c) and room-temperature photoluminescence (RT PL). The damage built up after implantation is found to be similar for Dy and Yb ions, but crystal structure recovery after annealing is more efficient for ZnO:Yb than for ZnO:Dy, when similar annealing conditions are applied. Colorimetric analysis of the RT PL spectra shows that (Dy,Yb) coimplantation allows shifting the optical response of ZnO:Dy films toward white color light. The correlated color temperature can be tuned in this way from 2500 to 3200 K, which makes these films attractive for indoor applications.