Electronic Polarization at Pentacene/Polymer Dielectric Interfaces: Imaging Surface Potentials and Contact Potential Differences as a Function of Substrate Type, Growth Temperature, and Pentacene Microstructure

2014 ◽  
Vol 118 (5) ◽  
pp. 2487-2497 ◽  
Author(s):  
Yanfei Wu ◽  
Greg Haugstad ◽  
C. Daniel Frisbie
Keyword(s):  
Growth Temperature ◽  
Substrate Type ◽  
Electronic Polarization ◽  
Contact Potential ◽  
Surface Potentials ◽  
Polymer Dielectric ◽  
Dielectric Interfaces

Adhesion strength measurement of polymer dielectric interfaces using laser spallation technique

2008 ◽  
Vol 516 (21) ◽  
pp. 7627-7635 ◽  
Author(s):  
Soma Sekhar V. Kandula ◽  
Cheryl D. Hartfield ◽  
Philippe H. Geubelle ◽  
Nancy R. Sottos
Keyword(s):  
Adhesion Strength ◽  
Strength Measurement ◽  
Laser Spallation ◽  
Polymer Dielectric ◽  
Dielectric Interfaces

Reduction of Defect Levels in Si and Si/Ce Layers Grown by MBE

1987 ◽  
Vol 102 ◽  
Author(s):  
C.J. Gibbings ◽  
D C.G. Tuppen
Keyword(s):  
Dislocation Density ◽  
Oxide Layer ◽  
Growth Temperature ◽  
Boron Oxide ◽  
Defect Density ◽  
Substrate Type ◽  
Factors Influencing ◽  
Dislocation Densities ◽  
Silicon Doped ◽  
P Type

ABSTRACTThe dislocation density in undoped Si-MBE layers grown on wafers without any chemical pre-cleaning has been studied. The oxide layer was removed using a low silicon flux. Factors influencing the dislocation density have been studied, including substrate type, growth temperature and the temperature at which oxide is removed. Dislocation densities below 10-3 cm-2 have been obtained. The defect density in p-type silicon doped with boron oxide has also been studied. The influence of boron oxide on dislocation density has been found to be negligible, even though incorporation of oxygen is large at growth temperatures ≤650°C. Boron oxide doped Si.88Ge.12 layers have also been grown and a similar level of dislocations has been found.

scholarly journals Phase boundary potentials of adsorbed films on metals.—Part III.—The examination of the interaction of copper and iodine vapour by the method of surface potentials

1933 ◽  
Vol 140 (842) ◽  
pp. 497-504 ◽  
Keyword(s):  
Diffusion Process ◽  
Phase Boundary ◽  
Noble Metals ◽  
Critical Thickness ◽  
Metal Substrate ◽  
Contact Potential ◽  
Adsorbed Film ◽  
Surface Potentials ◽  
Chemical Attack ◽  
Full Contact

With both platinum and gold, measurements by the method of surface potentials revealed the fact that at low temperatures iodine is reversibly adsorbed on the surface of these metals on which a film of chemi-adsorbed oxygen was present, and does not penetrate into or undergo chemical reaction with the metal substrate. With less noble metals it is known from the work of Kohlschütter and Krähenbtihl, of Tammann and especially Evans, that in spite of the presence of a thin layer of oxide which is invariably present, iodine readily attacks the metal, forming an iodide. The rate of attack is governed by a diffusion process through an ever-increasing thickness of solid, and the process is of the type designated as activated, in that the temperature coefficient of the diffusion process is exponential in character. After the exposure of a sheet of copper to the vapour of iodine we might anticipate that the phase boundary potential would be modified both by an adsorbed film of iodine on cuprous iodide, which adsorbed film should be readily volatile, as well as by a layer of cuprous iodide on the metal substrate. Further, the cuprous iodide is unstable (pseudomorphous form), and should in course of time become converted into a true cuprous iodide lattice (idiomorphous form), which later may undergo a process of sintering or crystallization. Since the iodide of copper is a semi-conductor it might be anticipated, from analogy with cuprous oxide and from the theory of formation of rectifying contacts suggested by Schottky and by Wilson that the full contact potential between the iodide and metal would not come into existence until the layer of pure insulating iodide attains a sufficient and critical thickness. Finally, if the idiomorphous as well as the pseudomorphous iodide form rectifying contacts with copper the conversion of the one into the other will affect the contact potential as well as the critical thickness required. It was thought desirable to examine the possibility of following the growth of a semi-conductor, formed by chemical attack at a metal surface, by the measurement of the phase boundary potentials.

Selective study of polymer/dielectric interfaces with vibrationally resonant sum frequency generation via thin-film interference

2002 ◽  
Vol 80 (17) ◽  
pp. 3084-3086 ◽  
Author(s):  
Philip T. Wilson ◽  
Kimberly A. Briggman ◽  
William E. Wallace ◽  
John C. Stephenson ◽  
Lee J. Richter
Keyword(s):  
Thin Film ◽  
Sum Frequency Generation ◽  
Sum Frequency ◽  
Polymer Dielectric ◽  
Dielectric Interfaces ◽  
Thin Film Interference ◽  
Frequency Generation

scholarly journals The structure of surface films XXI—Surface potentials of dibasic esters, alcohols, aldoximes, and ketones

1934 ◽  
Vol 147 (862) ◽  
pp. 491-499 ◽  
Keyword(s):  
Surface Potential ◽  
Organic Molecules ◽  
Dipole Moments ◽  
Surface Film ◽  
Carbon Chain ◽  
Surface Films ◽  
Contact Potential ◽  
Surface Potentials ◽  
Polar Groups ◽  
Derivatives Of

The object of this work was to obtain further information on several points affecting the dependence of surface potentials of unimolecular films on water surfaces, on the constitution and orientation of the molecules in the films. Measurements on the dibasic esters were expected to throw light on the relation between surface potential and density of packing of molecules in films of “gaseous” type; the measurements on alcohols, aldoximes, and methyl ketones were undertaken primarily in order to obtain values for the surface potential produced by the polar groups in these compounds, which could be compared with the potentials found with derivatives of the sterols, in which the same polar groups are attached to a complex ring system, instead of to an aliphatic straight carbon chain. The surface potential ΔV is the change in contact potential between the aqueous solution on which the film is spread, and air, caused by the presence of the surface film. The simplest basis of comparison is the quantity μ given by the equation ΔV = 4π n μ, n being the number of molecules per square centimetre of the films. If the dipoles of the film molecules were arranged as a parallel plate condenser in the surface, Kμ cos θ would be the dipole moment of the molecules, θ being the angle at which these dipoles are inclined to the vertical, and K the dielectric constant of the surface film. θ is in general unknown; but by comparsion of the highest values of μ obtained, with the values for the dipole moments of various polar groups in organic molecules obtained by other methods, it may be concluded that the value of K in the surface films is usually of the order 5 to 10.

InN-Based Ohmic Contacts to AlInN

1996 ◽  
Vol 449 ◽  
Author(s):  
S. M. Donovan ◽  
F. Ren ◽  
J. D. MacKenzie ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Growth Temperature ◽  
Electronic Structures ◽  
Ohmic Contacts ◽  
High Growth ◽  
Growth Conditions ◽  
Layer Growth ◽  
Substrate Type ◽  
Sapphire Substrates ◽  
The Impact

ABSTRACTIn order to maximize the performance of III-Nitride devices, it is necessary to develop thermally stable low resistance Ohmic contacts to III-N based electronic structures. This paper reports on the utility of InN as an aid to contact formation on widegap materials such as InAIN. For n-type materials, several questions relating to the growth conditions have been explored. Specifically, the impact of substrate type (GaAs vs. Sapphire), cap layer growth temperature and V/III ratio on contact resistance has been investigated. It was found that the use of sapphire substrates combined with high growth temperatures (575°C) and high V/III ratios produced acceptable contact resistances (∼10−6Ohm-cm2) to InAIN.

Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

1991 ◽  
Vol 49 ◽  
pp. 900-901 ◽  
Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber
Keyword(s):  
Transport Properties ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Lattice Parameter ◽  
Crystalline Quality ◽  
Insulating Properties ◽  
Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

Electrokinetic properties of metal-dielectric interfaces

1993 ◽  
Vol 140 (5) ◽  
pp. 385 ◽  
Author(s):  
T.J. Lewis ◽  
J.P. Llewellyn ◽  
M.J. van der Sluijs
Keyword(s):  
Electrokinetic Properties ◽  
Dielectric Interfaces
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