TY - JOUR
T1 - Photoluminescence and electron paramagnetic resonance of ZnO tetrapod structures
AU - Djurišić, Aleksandra B.
AU - Choy, Wallace C.H.
AU - Roy, Vellaisamy Arul Lenus
AU - Leung, Yu Hang
AU - Kwong, Chung Yin
AU - Cheah, Kok Wai
AU - Rao, Tumkur Krishnaswamy Gundu
AU - Chan, Wai Kin
AU - Lui, Hsian Fei
AU - Surya, Charles
PY - 2004/9
Y1 - 2004/9
N2 - ZnO tetrapod nanostructures have been prepared by the evaporation of Zn in air (no flow), dry and humid argon flow, and dry and humid nitrogen flow. Their properties have been investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies (at different temperatures), and electron paramagnetic resonance (EPR) spectroscopy at -160 °C and room temperature. It is found that the fabrication conditions significantly influence the EPR and PL spectra obtained. While a g=1.96 EPR signal is present in some of the samples, green PL emission can be observed from all the samples. Therefore, the green emission in our samples does not originate from the commonly assumed transition between a singly charged oxygen vacancy and a photoexcited hole [K. Vanheusden, C. H. Seager, W. L. Warren, D. R. Tallant, J. A. Voigt, Appl. Phys. Lett. 1996, 68, 403]. However, the green emission can be suppressed by coating the nanostructures with a surfactant for all fabrication conditions, which indicates that this emission originates from surface defects.
AB - ZnO tetrapod nanostructures have been prepared by the evaporation of Zn in air (no flow), dry and humid argon flow, and dry and humid nitrogen flow. Their properties have been investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies (at different temperatures), and electron paramagnetic resonance (EPR) spectroscopy at -160 °C and room temperature. It is found that the fabrication conditions significantly influence the EPR and PL spectra obtained. While a g=1.96 EPR signal is present in some of the samples, green PL emission can be observed from all the samples. Therefore, the green emission in our samples does not originate from the commonly assumed transition between a singly charged oxygen vacancy and a photoexcited hole [K. Vanheusden, C. H. Seager, W. L. Warren, D. R. Tallant, J. A. Voigt, Appl. Phys. Lett. 1996, 68, 403]. However, the green emission can be suppressed by coating the nanostructures with a surfactant for all fabrication conditions, which indicates that this emission originates from surface defects.
UR - http://www.scopus.com/inward/record.url?scp=6444233032&partnerID=8YFLogxK
U2 - 10.1002/adfm.200305082
DO - 10.1002/adfm.200305082
M3 - Article
AN - SCOPUS:6444233032
SN - 1616-301X
VL - 14
SP - 856
EP - 864
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 9
ER -