Spatially resolved optical activation of Eu ions by laser irradiation implanted hexagonal MoO3 microrods

An effective optical activation of Eu ions in implanted h-MoO3 microrods can be achieved by ultraviolet (325 nm) or red (633 nm) laser irradiation in a confocal microscope, contrary to the case of rapid thermal annealing or conventional annealing treatments. Eu3+ photoluminescence emission is triggered by h-MoO3 to alpha-MoO3 or h-MoO3 to eta-Mo4O11 phase transformations induced by the laser beam, as revealed by Raman microscopy and spectroscopy. The formation of such phases was found to depend on laser wavelength, power density, and irradiation time. The possibility to induce controlled activation of luminescent rare earth ions at a desired position and with high precision by laser irradiation is of interest for potential applications of this material in optoelectronics. Published by AIP Publishing.