HU Jun-tao, GUO Peng, MEI Jia-wei, GUO Chang-xin. Luminescent Properties After Annealing of Arrayed ZnO Sub-microrods Prepared by Two-step Chemical Solution Deposition[J]. Chinese Journal of Luminescence, 2006,27(2): 221-224
HU Jun-tao, GUO Peng, MEI Jia-wei, GUO Chang-xin. Luminescent Properties After Annealing of Arrayed ZnO Sub-microrods Prepared by Two-step Chemical Solution Deposition[J]. Chinese Journal of Luminescence, 2006,27(2): 221-224DOI:
ZnO materials are very promising for applications in field emission displays and photonic devices operating in blue and UV spectral ranges due to its wide band gap(3.37 eV) and large exciton binding energy(60 meV).Therefore
fabrication and properties of ZnO materials have attracted considerable attention.In this work
arrayed ZnO hexagonal sub-microrods have been synthesized onto glass substrates through a simple two-step chemical solution deposition by altering pH
the concentration of solution and other factors.XRD patterns
SEM images have been measured
which reveals almost of the ZnO microrods were highly orientated on thin films of ZnO template on the glass substrate and grown along the(002) direction.The diameter of the rods is in the range of 200~500 nm and the length of the rods is about several micro-meters.XRD patterns showed that the crystal structure of most of the ZnO sub-microrods is hexagonal structure.The luminescent properties of the ZnO sub-microrods which annealed at 650℃ with different time was investigated by excitation spectrum and photoluminescent spectrum.It revealed the excitation spectra of ZnO sub-microrods have a strong exciton excitation peak at 380 nm
and the blue default emission of the photoluminescent spectra have a blue-shift from 452 nm to 440 nm
the wide orange-red default emission intensity of the photoluminescent spectra become stronger with the peak red-shift from 630 nm to 720 nm with the annealing time increases.The PL spectra of ZnO have a blue peak at 430 nm and a green peak at 505 nm after annealing for 6 h.Compared the calculated data of these intrinsic defects with the theory of FP-LMTO
we attribute the green(505 nm)
orange-red(630 nm) and red(720 nm) emission to the transition from oxygen vacancies to the valence band
the blue emission peak at 440 nm to the transition from zinc interserts to the valence band.The enhancement of exciton excitation peak at 380 nm after annealing indicates that the energy transfer from the exciton to the defaultemission center occurred.