The Origin of Luminescence From Cerium Oxide on Silicon

1999 ◽  
Vol 560 ◽  
Author(s):  
Won Chel Choiv ◽  
Ho Nyung Lee ◽  
Yong Kim ◽  
Eun Kyu Kim
Keyword(s):  
Thin Films ◽  
Thermal Treatment ◽  
Cerium Oxide ◽  
Cerium Dioxide ◽  
Room Temperature ◽  
Ultra Violet ◽  
Blue Luminescence ◽  
Luminescent Material ◽  
Uv Emission ◽  
Thermally Treated

ABSTRACTAs the ultra-violet/blue luminescent material, we will introduce the thermal treated cerium oxide on silicon. It has been confirmed a violet/blue luminescence ranging from 358 rim to 450 rnm at room temperature from the thermally treated cerium-dioxide thin films on silicon. As a results of AES and HR-TEM measurement, it was confirmed that cerium silicates were generated by thermal treatment. These cerium silicates such as Ce4.667(SiO4)3O and Ce2Si2O7 are the source of the ultra-violet (UV) emission ranging from 358 nim to 450 nm (maximum at 388 rim).

Optical investigations on sputtered CuCl thin films

2005 ◽  
Vol 891 ◽  
Author(s):  
Gomathi Natarajan ◽  
Anirban Mitra ◽  
Lisa O'Reilly ◽  
Stephen Daniels ◽  
David C. Cameron ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Free Exciton ◽  
Ultra Violet ◽  
Rf Magnetron Sputtering ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Optical Absorbance ◽  
Uv Emission ◽  
Silicon Device

ABSTRACTCopper (I) chloride (CuCl) is a potential candidate for ultra violet optoelectronics due to the fact that it is closely lattice matched with silicon, which makes it readily integrable with silicon device technology. The structural and optoelectronic properties of CuCl thin films deposited by RF magnetron sputtering are investigated. The crystallinity is studied using X-ray diffraction which confirms the growth of CuCl thin films with cubic zinc blende structure predominantly orientated in <111> direction. Excitonic transitions in the thin films were thoroughly investigated using optical absorbance and luminescence spectroscopies. Room temperature absorption spectroscopic analysis confirms the existence of two exciton peaks namely Z12 and Z3 at 372 and 380 nm respectively. A strong UV emission is observed at room temperature in cathodoluminescence and photoluminescence spectra due to the recombination of Z3 exciton at approximately 384 nm. In the low temperature photoluminescence spectrum, a free exciton (Z3) and a bound exciton (I1) are observed. A variation of 1.3 nm to 10 nm was observed in the Z3 exciton line width from 10 K to 300 K.

Room-temperature blue luminescence from ZnO:Er thin films

2002 ◽  
Vol 413 (1-2) ◽  
pp. 257-261 ◽  
Author(s):  
X.T Zhang ◽  
Y.C Liu ◽  
J.G Ma ◽  
Y.M Lu ◽  
D.Z Shen ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Blue Luminescence

Effects of Ge-Implantation on the Photoluminescence of CuGaSe2 Thin Films

2005 ◽  
Vol 865 ◽  
Author(s):  
Serge Doka ◽  
Marin Rusu ◽  
Alex Meeder ◽  
Ernest Arushanov ◽  
Norbert Fabre ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Treatment ◽  
Ultra Violet ◽  
Surface Region ◽  
Vapor Transport ◽  
Treatment Results ◽  
Excitation Energies ◽  
Near Surface ◽  
Pl Spectra ◽  
Extrinsic Defects

AbstractPhotoluminescence (PL) spectra of as grown Ga-rich, and Ga-rich plus Ge-doped and annealed CCSVT (Chemical Close-Spaced Vapor Transport) — CuGaSe2 thin films have been investigated. Visible (514.5 nm) and Ultra- Violet (351.1 nm) excitation energies of the laser have been used in order to determine intrinsic and extrinsic defects created due to the implantation as well as separating near surface from bulk recombination.Both visible and UV-PL spectra of the undoped films show the well known luminescence of Ga-rich CuGaSe2, which can be described by the widely accepted model of fluctuating potentials. Unlike the visible- and UV-PL emissions of Ge- implanted and annealed films differ strongly. Obviously, Ge-implantation in combination with the thermal treatment results in an extrinsic doping of the material producing so far unknown states in the CuGaSe2 band gap. Comparing the visible- and the UV-PL spectra we found an accumulation of these extrinsic doping levels in the near-surface-region of the films.

Photoluminescence from Gd-implanted AlN and GaN Epilayers

2006 ◽  
Vol 955 ◽  
Author(s):  
John M Zavada ◽  
Neeraj Nepal ◽  
J. Lin ◽  
K. H. Kim ◽  
H. X. Jiang ◽  
...  
Keyword(s):  
Thin Films ◽  
Emission Intensity ◽  
Emission Band ◽  
Ultra Violet ◽  
Sample Temperature ◽  
Temperature Range ◽  
Ti:Sapphire Laser ◽  
Uv Emission ◽  
Pl Emission

ABSTRACTGaN and AlN thin films were implanted with gadolinium (Gd)atoms and characterized using deep ultra-violet (UV) photoluminescence(PL). The Gd-implanted samples were annealed at temperatures up to 1178K in a flowing N2 gas to facilitate recovery of implantation-related damage. Using the output at 195 nm from a quadrupled Ti:sapphire laser, narrow PL emission was observed at 318 nm from the Gd- implanted AlN thin films. This emission is characteristic of the lowest energy 4f transition of the trivalent Gd ion. A boarder emission band, also centered at 318 nm, was observed under excitation at 266 nm. No PL emission was observed from the Gd-implanted GaN thin films at either the bandedge or due to a 4f transition. The dependence of the UV emission on AlN sample temperature was systematically studied. The peak PL emission intensity decreased by less that a factor of 3 over the temperature range of 10 K to 300 K. Decay transients of the UV emission were measured indicating that the lifetime of this emission is very fast.

Investigation on the Optical Performance of Co and Al Co-Doping ZnO Films

2013 ◽  
Vol 275-277 ◽  
pp. 1941-1945
Author(s):  
Gen Zong Song ◽  
Duo Zhang
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Thermal Treatment ◽  
Room Temperature ◽  
Treatment Temperature ◽  
Ultraviolet Absorption ◽  
Zno Films ◽  
Thermal Treatment Temperature ◽  
Doped Zno ◽  
Co Doped

ZnO is a novel kind of semiconductor material, which has hexagonal Wurtzite crystal structure, with a wide band-gap of 3.37eV at room temperature. It owns a large excitation binding energy of 60meV and excellent room temperature stability. ZnO has very useful properties of piezoelectricity, gas & pressure sensitivity etc. Therefore, application researches on low dimensional ZnO materials have become hot topics and significant values.In this paper, ZnO doped thin films were prepared by sol-gel method. Zn (CH3COO)2•2H2O was employed as the precursor, anhydrous alcohol was the solvent, monoethanolamine was the complexant, Co(CH3COO)2•4H2O was used as the source of the Co-dopant, Al(NO3)3•9H2O was used as the source of the Al-dopant in the experiment to yield the doped ZnO films. The sample preparation spin coating number is 6, the average grain size is in nanometer level, and the thermal treatment temperature is 450, 500, 550, 600°C, respectively. The effect of the doping proportion on the crystallization and energy band structure of the ZnO thin films were characterized by X-ray diffraction (XRD), the Infrared spectrum and the ultraviolet-visible transmission spectra (UV-Vis).The results show that the crystalline grain size of the ZnO doped films grown on glass substrates increases, since the thermal treatment temperature rise. In this paper, a best ZnO doped film was obtained at the temperature of 600°C. It preliminarily analyses that Co-doped ZnO films present a absorption peak in infrared area when the thermal treatment is at 550°C. Al or Co doped ZnO films can cause a redshift of ultraviolet absorption peaks. Energy gap is around 3.2eV when doped. The ultraviolet absorption peaks of Al-doped ZnO films will have a shift to high energy, since it has a better crystallinity.

scholarly journals Room-temperature blue luminescence of thermally oxidized Si1−x−yGexCy thin films on Si (100) substrates

1999 ◽  
Vol 75 (21) ◽  
pp. 3333-3335 ◽  
Author(s):  
Xuemei Cheng ◽  
Youdou Zheng ◽  
Xiabing Liu ◽  
Lan Zang ◽  
Zhiyun Lo ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Blue Luminescence

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

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