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.

Pulsed Ion Beam Annealing of Metal and Silicide Thin Films on Silicon

1982 ◽  
Vol 40 ◽  
pp. 458-459
Author(s):  
L.J. Chen ◽  
L.S. Hung ◽  
J.W. Mayer
Keyword(s):  
Thin Films ◽  
Ion Beam ◽  
Surface Region ◽  
Molten Layer ◽  
Near Surface ◽  
Contact Materials ◽  
Energy Beam ◽  
Nickel Thin Films ◽  
Metal Silicides ◽  
Silicide Growth

Metal silicides have found increasing use in microelectronic industry as contact materials. Energy beam annealing offers controlled energy deposition in the near surface region so that silicide growth is achieved without heating the entire layer. When pulsed laser and electron at high power density were applied to metal-semiconductor systems, cellular structures have been formed with silicon columns surrounded by silicide walls as a result of the formation of the molten layer of metal and silicon followed by segregation due to constitutional supercooling as the melt front moves toward the surface. A wealth of microstructures were observed in pulsed ion beam annealed nickel thin films on silicon. An interface melting mechanism was invoked to explain the results. In this paper, we report further data on the subject.

The Effects of Kcn Etching on Cu-Rich Epitaxial CuInSe2 Thin Films

1996 ◽  
Vol 426 ◽  
Author(s):  
P. Fons ◽  
S. Nikl ◽  
A. Yamada ◽  
M. Nishitanp ◽  
T. Wada ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Region ◽  
Etching Time ◽  
Cation Sublattice ◽  
Epitaxial Thin Films ◽  
Near Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Integrated Intensity

AbstractA series of Cu-rich CuInSe2 epitaxial thin films were grown by molecular beam epitaxy on GaAs(001) substrates from elemental sources at a growth temperature of 450 °C. All samples were grown with an excess of Cu. Electron microprobe analysis (EPMA) indicated a Cu/ In ratio of about 2.1–2.6 in the as-grown films. Additionally, the Se/ (In+Cu) ratio was observed to be ∼0.95 indicating that the films were slightly Se poor. These Cu-rich samples were etched in a KCN solution for periods ranging from 30 seconds to 3 minutes. EPMA measurements indicated that the bulk Cu/ In ratio was reduced to ∼0.92 in all films regardless of etching time. Atomic force microscopy (AFM) was used to characterize the topology of each sample before and after etching. These measurements indicated that the precipitates present on the as-grown films were removed and large nearly isotropic holes were etched into the sample to a depth of over 1000 Å even for etching times as short as 30 seconds. The samples were also evaluated both before and after etching using a Phillips MRD diffractometer with parallel beam optics and a 18,000 watt Cu rotating anode X-ray source in the chalcopyrite [001], [101], and [112] directions. A peak was observed at ∼15 degrees in the [001] scan after etching consistant with the presence of the ordered vacancy compound, CuIn3Se5. Additionally the integrated intensity ratios of the chalcopyrite (202) reflection to the chalcopyrite (101) reflection ∝(fCu-fIn)2 along the [101] direction indicated the presence of a near-surface region containing cation sublattice disorder that was subsequently removed by the etching process.

Enhanced high-frequency molecular dynamics in the near-surface region of polystyrene thin films observed with β-NMR

Soft Matter ◽  
2015 ◽  
Vol 11 (9) ◽  
pp. 1755-1761 ◽  
Author(s):  
Iain McKenzie ◽  
Chad R. Daley ◽  
Robert F. Kiefl ◽  
C. D. Philip Levy ◽  
W. Andrew MacFarlane ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
High Frequency ◽  
Surface Region ◽  
Near Surface

Fabrication of CaWO4:Eu3+ Thin Films via Electrochemical Methods Assisted by a Novel Post Treatment

2011 ◽  
Vol 194-196 ◽  
pp. 2458-2461 ◽  
Author(s):  
Lian Ping Chen ◽  
Yuan Hong Gao ◽  
Jian Xiong Yuan ◽  
Qing Hua Zhang ◽  
Yan Hong Yin ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Electrochemical Techniques ◽  
Surface Region ◽  
Luminescent Properties ◽  
Emission Peak ◽  
X Ray Diffraction ◽  
Near Surface ◽  
X Ray ◽  
Rare Earth Doped

It is hardly possible to obtain rare earth doped CaWO4 thin films directly through electrochemical techniques. A novel post processing has been proposed to synthesize CaWO4:Eu3+ thin films at room temperature. X-ray diffraction, X-ray photoelectron spectrometry, spectrophotometer were used to characterize their phase, composition and luminescent properties. Results reveal that Eu3+-doped CaWO4 films have a tetragonal phase; the content of Eu in the near surface region is much higher than that of the bulk; under the excitation of 310 nm, a sharp emission peak at 616 nm has been observed for Ca0.9WO4:Eu0.13+ thin films.

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).

Reactions at the interface between multi-component glasses and metallic lithium films

1989 ◽  
Vol 4 (4) ◽  
pp. 978-989 ◽  
Author(s):  
K. R. Zavadil ◽  
N. R. Armstrong ◽  
C. H. F. Peden
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Surface Region ◽  
Alloy Formation ◽  
Sodium Potassium ◽  
Near Surface ◽  
Network Modifier ◽  
X Ray ◽  
Metallic Lithium

The reactions of vacuum deposited thin films of lithium with various complex glasses have been explored using x-ray photoelectron spectroscopy (XPS). In contrast to lithium reactions with simple glasses such as silica or boron oxides, the reactions are predominantly those of the network modifiers such as sodium, potassium, and magnesium. XPS and x-ray induced Auger lineshapes indicate the migration of the network modifier to the near surface region followed by its reduction. In the case of magnesium, there is evidence for stable alloy formation with unreacted lithium following these migration and reduction steps.

Structural analysis of coexisting tetragonal and rhombohedral phases in polycrystalline Pb(Zr0.35Ti0.65)O3 thin films

2003 ◽  
Vol 18 (1) ◽  
pp. 173-179 ◽  
Author(s):  
Maxim B. Kelman ◽  
Paul C. McIntyre ◽  
Bryan C. Hendrix ◽  
Steven M. Bilodeau ◽  
Jeffrey F. Roeder ◽  
...  
Keyword(s):  
Thin Films ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
Surface Region ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
Near Surface ◽  
X Ray ◽  
Scattering Geometry ◽  
Pzt Films

Structural properties of polycrystalline Pb(Zr0.35Ti0.65)O3 (PZT) thin films grown by metalorganic chemical vapor deposition on Ir bottom electrodes were investigated. Symmetric x-ray diffraction measurements showed that as-deposited 1500 íthick PZT films are partially tetragonal and partially rhombohedral. Cross-section scanning electron microscopy showed that these films have a polycrystalline columnar microstructure with grains extending through the thickness of the film. X-ray depth profiling using the grazing-incidence asymmetric Bragg scattering geometry suggests that each grain has a bilayer structure consisting of a near-surface region in the etragonal phase and the region at the bottom electrode interface in the rhombohedral hase. The required compatibility between the tetragonal and rhombohedral phases in he proposed layered structure of the 1500 Å PZT can explain the peak shifts observed n the symmetric x-ray diffraction results of thicker PZT films.

Soft X‐Ray Studies of Y‐Ba‐Cu‐O Thin Films Prepared by Laser Ablation

1989 ◽  
Vol 169 ◽  
Author(s):  
A. Krol ◽  
C.J. Sher ◽  
D.R. Storch ◽  
L.W. Song ◽  
Y.H. Kao ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Parallel Plate ◽  
Surface Region ◽  
Angular Variation ◽  
Near Surface ◽  
X Ray ◽  
20 Nm ◽  
First Time ◽  
Oxygen Atoms

AbstractAngular variation of x‐ray fluorescence due to oxygen atoms in high‐T Y‐Ba‐Cu‐O thin films is measured for the first time by using a new parallel plate avalanche chamber. This technique allows the possibility of nondestructive probing of the depth‐profile of oxygen atoms in the superconducting materials. Our preliminary results indicate that the near surface region of the Y‐Ba‐Cu‐O film may contain an oxygen‐depleted layer of thickness around 20 nm.

A technique to prepare cross-sectional TEM specimens of semiconducting devices

1986 ◽  
Vol 44 ◽  
pp. 742-743
Author(s):  
A. K. Rai ◽  
P. P. Pronko
Keyword(s):  
Thin Films ◽  
Surface Region ◽  
Sample Surface ◽  
Specific Region ◽  
Cross Sectional ◽  
Thin Sections ◽  
The Past ◽  
Device Structures ◽  
Ion Implanted

Several techniques have been reported in the past to prepare cross(x)-sectional TEM specimen. These methods are applicable when the sample surface is uniform. Examples of samples having uniform surfaces are ion implanted samples, thin films deposited on substrates and epilayers grown on substrates. Once device structures are fabricated on the surfaces of appropriate materials these surfaces will no longer remain uniform. For samples with uniform surfaces it does not matter which part of the surface region remains in the thin sections of the x-sectional TEM specimen since it is similar everywhere. However, in order to study a specific region of a device employing x-sectional TEM, one has to make sure that the desired region is thinned. In the present work a simple way to obtain thin sections of desired device region is described.

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