Directed growth characteristics and optoelectronic properties of Eu-doped ZnO nanorods and urchins

Inexpensive fabrication of europium (Eu(3+))-doped zinc oxide (ZnO) nanoparticles, nanorods, and urchin systems obtained by rapid thermal annealing is being reported. The polyvinyl alcohol films containing a reactant mixture [Zn(CH(3)COO)(2), Eu(CH(3)COO)(3), and NaOH] were casted on Al-foils followed by thermal annealing at 80, 300, and 650 degrees C. Gradual change-over from spheriCally symmetric nanoparticles to nanorods along with urchin like structures are obtained under different annealing environment. The nanorods and urchins are expected to have grown as a result of spontaneous decomposition of Zn(OH)(2) followed by unidirectional growth. The nanorods are dislodged from the regular urchin structures at a high annealing temperature of 650 degrees C because of the loss of the crystalline substrate support. The as-received ZnO products possessed hexagonal wurtzite structure for all the annealing cases-as evident from the x-ray diffraction patterns. The photoluminescence study on the samples has revealed dominant defect related emissions compared to the near band edge emission. The band edge emission (similar to 382 nm) is recovered in the urchin systems whereas Eu(3+) related transitions observed at similar to 591 nm ((5)D(0)->(7)F(1)) and similar to 613 nm ((5)D(0)->(7)F(2)) remained intact with structural modification. (C) 2010 American Institute of Physics. [doi:10.1063/1.3462396]