Direct observation of x-ray radiation-induced damage to SiO2/Si interface using multiwavelength room temperature photoluminescence

Author(s):  
Jae Hyun Kim ◽  
Je Young Park ◽  
Chang Hwan Lee ◽  
Yeo Jin Yoon ◽  
Jin San Yoo ◽  
...  
2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.


2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Yan Li ◽  
Chuan-Sheng Liu ◽  
Yun-Ling Zou

AbstractZnO nano-tubes (ZNTs) have been successfully synthesized via a simple hydrothermal-etching method, and characterized by X-ray diffraction, field emission scanning electron microscopy and room temperature photoluminescence measurement. The as-synthesized ZNTs have a diameter of 500 nm, wall thickness of 20–30 nm, and length of 5 µm. Intensity of the plane (0002) diffraction peak, compared with that of plane (10$$ \bar 1 $$0) of ZNTs, is obviously lower than that of ZnO nano-rods. This phenomenon can be caused by the smaller cross section of plane (0002) of the nano-tubes compared with that of other morphologies. On basis of the morphological analysis, the formation process of nano-tubes can be proposed in two stages: hydrothermal growth and reaction etching process.


1968 ◽  
Vol 23 (2) ◽  
pp. 126-133 ◽  
Author(s):  
Werner F. Schmidt

Electrical conductivity measurements were made for the determination of G (free ions) in some hydrocarbons. The radiation source was a x-ray tube operated at 55 kV. Four quantities were measured for each liquid: 1. the stationary electrical conductivity at low electric field strength during irradiation, 2. the mobilities of the radiation-induced ions, 3. the volume recombination coefficient, and 4. the absorbed dose rate.All measurements were performed with aerated liquids at room temperature. The following G-values were obtained: n-pentane 0,1; n-hexane and n-heptane 0,09; iso-octane 0,11; cyclohexane 0,06; benzene 0,07; decalin 0,04. The standard deviation was estimated to ± 25 per cent.


1998 ◽  
Vol 510 ◽  
Author(s):  
S.P. Watkins ◽  
X. Xu ◽  
J. Hu ◽  
R. Ares ◽  
P. Yeo ◽  
...  

AbstractWe have performed a systematic study of the effect of various phosphorus passivation techniques on the room temperature photoluminescence (PL) intensity of undoped GaAs. The effects of passivation by two methods are compared: (1) the P-exchange reaction on exposure to tertiarybutylphosphine (TBP) vapour between 500-620°C, and (2) the growth of thin layers of GaP directly on GaAs. An x-ray diffraction technique was used to estimate the thickness of the passivating layers. Reflectance difference spectroscopy indicated a similar chemical origin for the two passivation methods. Both passivation techniques resulted in strong enhancements in the room temperature PL. PL intensity was observed to increase very rapidly with adsorbed P for both cases saturating at approximately 2 monolayers equivalent GaP coverage.


2010 ◽  
Vol 24 (32) ◽  
pp. 3081-3087 ◽  
Author(s):  
GENGPING WAN ◽  
GUIZHEN WANG

Lead tungstate ( PbWO 4) microcrystals with hierarchical structures have been successfully synthesized via a facile microwave irradiation heating method. The cetyltrimethylammonium bromine (CTAB) and microwave-heated power were found to play an important role in the morphological control of resulting PbWO 4 mirocrystals. The products were characterized by the techniques of powder X-ray diffraction and field-emission scanning electron microscopy. A growth mechanism of PbWO 4 microstructures was proposed. The luminescence properties of the final products were investigated and the as-prepared PbWO 4 microcrystals displayed a very unique room-temperature photoluminescence compared to the reported results.


1993 ◽  
Vol 57 (1-6) ◽  
pp. 105-109 ◽  
Author(s):  
E. Bustarret ◽  
I. Mihalcescu ◽  
M. Ligeon ◽  
R. Romestain ◽  
J.C. Vial ◽  
...  

2010 ◽  
Vol 24 (10) ◽  
pp. 945-951 ◽  
Author(s):  
LIWEI WANG ◽  
ZHENG XU ◽  
SULING ZHAO ◽  
LIFANG LU ◽  
FUJUN ZHANG

ZnO : V thin films with different doping concentration (0%, 1.8%, 3.9%, 6.8%, 10%, and 13%) were fabricated by direct current magnetron sputtering. The X-ray diffraction patterns show that the wurzite structure changed with doping concentration. Furthermore, we could not find any vanadium cluster or phase separation in the X-ray diffraction patterns. The photoluminescence of ZnO : V with different vanadium concentration was investigated. The room temperature photoluminescence spectrum indicates that the films have purple band with 370 nm and the bands with 475 and 490 nm. The peak intensity of room temperature photoluminescence spectrum was affected by vanadium contents and its position remained stable. The intensity of band with 370 nm increases with raising the vanadium concentration and then decreases. The hysteresis behavior indicates that films were ferromagnetic at 50 K. Room temperature ferromagnetism was observed for the film with the doping concentration at 6.8%. However, in this case almost no hysteresis is noticeable. The results implied that the doping concentration and crystalline microstructure influence strongly the film's magnetic characteristics. Increasing the vanadium content in the film caused the degradation of the magnetic ordering.


1994 ◽  
Vol 358 ◽  
Author(s):  
Paul wickboldt ◽  
Hyeonsik M. Cheong ◽  
Dawen Pang ◽  
Joseph H. Chen ◽  
William paul

ABSTRACTSiOx nanoclusters (7 nm to 17 nm) are produced by evaporation of SiO (or Si) in Ar (+O2) atmospheres. Room temperature photoluminescence (PL) measurements in vacuum reveal a broad band centered at 1.65 eV. Upon exposure to gas this PL band is extinguished in a matter of seconds, and another band centered at 2.12 eV appears. This effect occurs regardless of the gas used (He, Ar, N2, O2, H2O vapor or air) and is entirely reversible upon evacuation.Transmission electron microscopy (TEM), Raman, infrared transmission, and X-ray photoluminescence spectroscopy (XPS) measurements are used to characterize the clusters. They are noncrystalline, and the oxidation state is a suboxide rather than SiO2 The PL spectra are independent of cluster size. The PL does not occur without sufficient oxidation and does not require the presence of bonded hydrogen. We are led to speculate that the radiative recombination occurs in electron states derived from a suboxide.


2007 ◽  
Vol 31 ◽  
pp. 114-116 ◽  
Author(s):  
N.D. Chien ◽  
H.V. Chung ◽  
P.T. Huy ◽  
Do Jin Kim ◽  
Maurizio Ferrari

Manganese (Mn) and copper (Cu) doping of ZnS nanowires was achieved by thermal evaporation of Mn, Cu doped ZnS nanopowders. Field emission scanning electron microscopy, and X-ray diffraction studies of the obtained ZnS nanowires demonstrate that the nanowires are single crystal structures and have diameters about 30-200 nm and lengths up to 1 millimeter. Room temperature photoluminescence (PL) measurements show a common PL peak around 520 nm for all ZnS nanowires samples, while impurity-related emission band are observed in doped ZnS nanowires. The dependence of the PL intensity on Mn doping concentration has also been investigated. It is shown that for high Mn doping concentration (10%) in the starting ZnS nanopowders, new emission bands (orange-red and red bands) are observed from the ZnS:Mn nanowires products. The origins of these new emission bands are discussed and brought up for further discussion.


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