Anisotropic x-ray absorption effects in the optical luminescence yield of ZnO nanostructures

2006 ◽  
Vol 89 (9) ◽  
pp. 093118 ◽  
Author(s):  
R. A. Rosenberg ◽  
G. K. Shenoy ◽  
L.-C. Tien ◽  
D. Norton ◽  
S. Pearton ◽  
...  
Keyword(s):  
Zno Nanostructures ◽  
X Ray ◽  
Optical Luminescence ◽  
Luminescence Yield ◽  
X Ray Absorption

Optical Luminescence Yield X-ray Absorption Fine Structures at the Sulphur and Silicon K-edge

1993 ◽  
Vol 32 (S2) ◽  
pp. 223 ◽  
Author(s):  
T. K. Sham ◽  
X.-H. Feng ◽  
D.-T. Jiang ◽  
K. H. Tan ◽  
S. P. Frigo ◽  
...  
Keyword(s):  
X Ray ◽  
Absorption Fine ◽  
Optical Luminescence ◽  
Luminescence Yield ◽  
Fine Structures ◽  
X Ray Absorption

Cathodoluminescence, X-ray excited optical luminescence, and X-ray absorption near-edge structure studies of ZnO nanostructures

2012 ◽  
Vol 90 (3) ◽  
pp. 298-305 ◽  
Author(s):  
Olga Lobacheva ◽  
Patricia L. Corcoran ◽  
Michael W. Murphy ◽  
Jun Young Peter Ko ◽  
Tsun-Kong Sham
Keyword(s):  
Gas Flow ◽  
Branching Ratio ◽  
Optical Emission ◽  
Zno Nanostructures ◽  
Edge Structure ◽  
X Ray ◽  
Synthesis Parameters ◽  
Optical Luminescence ◽  
Carrier Gas Flow ◽  
X Ray Absorption

ZnO nanostructures of various morphologies and crystallinities were fabricated by thermal evaporation from Zn powder in a tube furnace in the presence of oxygen. It was found that the morphology of ZnO nanostructures was affected by synthesis parameters, such as growth temperature, carrier gas flow, and the presence of catalyst on the surface of the substrate. Representative ZnO nanostructures were studied by X-ray excited optical luminescence (XEOL) and cathodoluminescence (CL) methods. The luminescence from these samples exhibits a morphology dependence of the branching ratio of the near band gap (NBG) emission in the UV and defect emission in the green (GE). The appearance of the optical emission also depends on the excitation method. X-ray absorption near-edge structures (XANES) at the O K-edge and Zn L-edge are also presented and their implications discussed.

Morphology-dependent luminescence from ZnO nanostructures — An X-ray excited optical luminescence study at the Zn K-edge

2009 ◽  
Vol 87 (9) ◽  
pp. 1255-1260 ◽  
Author(s):  
Olga Lobacheva ◽  
Michael W. Murphy ◽  
Jun Young Peter Ko ◽  
Tsun-Kong Sham
Keyword(s):  
Gas Flow ◽  
Thermal Evaporation ◽  
Growth Conditions ◽  
Zno Nanostructures ◽  
Edge Structure ◽  
X Ray ◽  
Si Substrates ◽  
Optical Luminescence ◽  
Carrier Gas Flow ◽  
X Ray Absorption

ZnO nanostructures have been synthesized by thermal evaporation on Si substrates. It is found that the morphologies of the nanostructures are governed by growth conditions such as temperature, carrier-gas flow rate, and the nature of the substrate (with and without a catalyst). We report X-ray excited optical luminescence from ZnO nanostructures of distinctly different morphologies in the energy and time domain using excitation photon energies across the Zn K-edge. X-ray excited optical luminescence (XEOL) and X-ray absorption near edge structure (XANES) study has clearly shown the morphology dependence of the ZnO optical properties. A correlation of luminescence with morphology, size, and crystallinity emerges.

VUV- and Soft X-Ray-Induced Optical Luminescence and X-Ray Absorption Fine Structures of Porous Silicon

1992 ◽  
Vol 281 ◽  
Author(s):  
T. K. Sham ◽  
D. T. Jiang ◽  
I. Coulthard ◽  
J. W. Lorimer ◽  
X. H. Feng ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Total Electron Yield ◽  
Total Electron ◽  
X Ray ◽  
Absorption Fine ◽  
Electron Yield ◽  
Optical Luminescence ◽  
Fine Structures ◽  
X Ray Absorption ◽  
Uv Excitation

ABSTRACTOptical luminescence in porous silicon induced by soft X-ray and vacuum UV excitation with energies in the vicinity of the Si K-edge (1838 eV) and the Si L-edge (99 eV) has been observed. The luminescence has been used, together with total electron yield, to record X-ray absorption fine structure (XAFS) in the near-edge region of both Si edges. The near- edge spectra recorded simultaneously with either luminescence or total electron yield were compared, and the implications of these measurements for the structure of porous silicon are discussed.

Optical-luminescence yield spectra produced by x-ray excitation

1993 ◽  
Vol 47 (12) ◽  
pp. 6918-6930 ◽  
Author(s):  
Shuichi Emura ◽  
Toshihiro Moriga ◽  
Jun Takizawa ◽  
Masaharu Nomura ◽  
Karl Rudolf Bauchspiess ◽  
...  
Keyword(s):  
X Ray ◽  
Optical Luminescence ◽  
Luminescence Yield

Condensation of silicon nanowires from silicon monoxide by thermal evaporation — An X-ray absorption spectroscopy investigation

2007 ◽  
Vol 85 (10) ◽  
pp. 695-701 ◽  
Author(s):  
P -SG Kim ◽  
Y -H Tang ◽  
T K Sham ◽  
S T Lee
Keyword(s):  
Silicon Nanowires ◽  
Thermal Evaporation ◽  
Silicon Monoxide ◽  
Starting Material ◽  
Oxidation States ◽  
X Ray ◽  
Absorption Fine ◽  
Optical Luminescence ◽  
Fine Structures ◽  
X Ray Absorption

We report a Si K-edge X-ray absorption fine structures (XAFS) study of silicon monoxide (SiO), the starting material for silicon nanowire preparation, its silicon nanowires, and the residue after the preparation of the starting material. The silicon nanowires were condensed onto three different substrates, (i) the wall of the furnace quartz tube, (ii) a porous silicon substrate, and (iii) a Si(100) silicon wafer. It was found that the Si K-edge XAFS of SiO exhibits identifiable spectral features characteristic of Si in 0 and 4 oxidation states as well as in intermediate oxidation states, while the SiO residue primarily shows features of Si(0) and Si(4). The XAFS suggest that SiO is not exactly a simple mixture of Si and SiO2. The silicon nanowires produced by the process exhibit morphology and luminescence property variations that depend on the nature of the substrate. X-ray excited optical luminescence (XEOL) at the O K-edge suggests an efficient energy transfer to the optical decay channel. The results and their implications are discussed.Key words: silicon nanowires, thermal evaporation, silicon monoxide, X-ray absorption fine structures, X-ray excited optical luminescence.

Site-selective x-ray absorption fine structure analysis of an optically active center in Er-doped semiconductor thin film using x-ray-excited optical luminescence

2001 ◽  
Vol 78 (2) ◽  
pp. 183-185 ◽  
Author(s):  
Masashi Ishii ◽  
Yoshihito Tanaka ◽  
Tetsuya Ishikawa ◽  
Shuji Komuro ◽  
Takitaro Morikawa ◽  
...  
Keyword(s):  
Thin Film ◽  
Fine Structure ◽  
Active Center ◽  
Optically Active ◽  
X Ray ◽  
Optical Luminescence ◽  
Semiconductor Thin Film ◽  
Er Doped ◽  
Site Selective ◽  
X Ray Absorption
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