scholarly journals Band filling and depletion through the doping of polyaniline thin films

2002 ◽  
Vol 80 (23) ◽  
pp. 4342-4344 ◽  
Author(s):  
B. Xu ◽  
Jaewu Choi ◽  
A. N. Caruso ◽  
P. A. Dowben
Keyword(s):  
Thin Films ◽  
Band Filling

Optical Nonlinearity of Sputtered Co3O4-SiO2-TiO2 Thin Films

2001 ◽  
Vol 703 ◽  
Author(s):  
Hiroki Yamamoto ◽  
Takashi Naito ◽  
Kazuyuki Hirao
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Excited State ◽  
Absorption Coefficient ◽  
Extinction Coefficient ◽  
Ground State ◽  
Optical Nonlinearity ◽  
Tio2 Thin Films ◽  
Change Mechanism ◽  
Band Filling

ABSTRACTOptical non-linearity of cobalt oxide with SiO2-TiO2 additives was investigated, and the change mechanism of the refractive index (n) and extinction coefficient (k), based on the relation between band structure and optical non-linearity of the thin films, was discussed. Refractive index and extinction coefficient of Co3O4 thin films in the ground state were 3.17 and 0.42, respectively. Both n and k decreased by irradiation from a pulse laser with 650 nm of wavelength (1.91eV). These values in the excited state were 2.91 and 0.41, respectively. n2 estimated from the change of n and k was −2.8 ×10−11 m2/W. The film had a band gap corresponding to 2.06eV, indicating that it was widened by the band filling effect during the laser irradiation at 1.91eV, and this led to the decrease in absorption coefficient and refractive index.

scholarly journals Tuning plasmonic properties of CuS thin films via valence band filling

RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 11118-11122 ◽  
Author(s):  
Shankara S. Kalanur ◽  
Hyungtak Seo
Keyword(s):  
Thin Films ◽  
Electrochemical Reduction ◽  
Valence Band ◽  
Hole Concentration ◽  
Band Filling

Tuning plasmonic properties of CuS thin films via electrochemical reduction by decreasing hole concentration in the valence band.

Optical and Electrical Properties of Gallium-Doped Mg15Zn85O Thin Films

2006 ◽  
Vol 957 ◽  
Author(s):  
Wei Wei ◽  
Vikram Bhosle ◽  
Chunming Jin ◽  
Roger J Narayan
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Fused Silica ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Gallium Concentration ◽  
Band Filling ◽  
Absorption Measurements

ABSTRACTGa-doped Mg0.15Zn0.85O thin films have been grown on fused silica substrates at 350°C with four different gallium concentration values using pulsed laser deposition. X-ray diffraction results indicate that these films were textured with c-plane parallel to the substrate surface. The bandgap of the films were determined based on the absorption measurements. The bandgaps of the Ga-doped thin films shifted to higher energy with respect to that of the unalloyed Mg0.15Zn0.85O thin film due to the band filling effect of electron distribution in the conduction band. Resistivity of the films was measured with four-point probe at temperatures from 295 K to 15 K. The activation energy of the gallium dopants was extracted by fitting the temperature dependent curve of resistivity.

scholarly journals Effect of band filling on anomalous Hall conductivity and magneto-crystalline anisotropy in NiFe epitaxial thin films

AIP Advances ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 015101 ◽  
Author(s):  
Zhong Shi ◽  
Hang-Yu Jiang ◽  
Shi-Ming Zhou ◽  
Yan-Liang Hou ◽  
Quan-Lin Ye ◽  
...  
Keyword(s):  
Thin Films ◽  
Hall Conductivity ◽  
Epitaxial Thin Films ◽  
Crystalline Anisotropy ◽  
Band Filling ◽  
Magneto Crystalline Anisotropy

The study of interfacial reactions of nickel thin films on GaAs

1983 ◽  
Vol 41 ◽  
pp. 156-157
Author(s):  
L.J. Chen ◽  
Y.F. Hsieh
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Interfacial Reactions ◽  
Metal Contacts ◽  
Nickel Thin Films ◽  
Thin Foils ◽  
The Status ◽  
Si Doped ◽  
Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

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.

Nucleation and Early Growth of Sputtered thin Films

1970 ◽  
Vol 28 ◽  
pp. 516-517
Author(s):  
Dudley M. Sherman ◽  
Thos. E. Hutchinson
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
Ion Beam ◽  
Ion Source ◽  
Water Cooling ◽  
Stages Of Growth ◽  
Lens Assembly ◽  
Microscope Technique ◽  
Ion Beam Sputter Deposition

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.

Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

1983 ◽  
Vol 41 ◽  
pp. 606-607
Author(s):  
Klaus-Ruediger Peters ◽  
Samuel A. Green
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Critical Point ◽  
Metal Films ◽  
High Magnification ◽  
Osmium Impregnation ◽  
Instrumental Resolution ◽  
20 Nm ◽  
Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

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