LANGMUIR–BLODGETT FILMS AND MOLECULAR ELECTRONICS

2009 ◽  
Vol 23 (29) ◽  
pp. 3437-3451 ◽  
Author(s):  
SYED-ARSHAD HUSSAIN ◽  
D. BHATTACHARJEE
Keyword(s):  
Molecular Electronics ◽  
Molecular Level ◽  
Film Deposition ◽  
Main Concern ◽  
Preparation Technique ◽  
Langmuir Blodgett ◽  
Lb Film ◽  
Interdisciplinary Field ◽  
Langmuir Blodgett Films ◽  
The Subject

Molecular electronics is a new, exciting and interdisciplinary field of research. The main concern of the subject is to exploit the organic materials in electronic and optoelectronic devices. On the other hand, the Langmuir–Blodgett (LB) film deposition technique is one of the best among few methods used to manipulate materials at the molecular level. In this article, the LB film preparation technique is discussed briefly with an emphasis on its application towards molecular electronics.

A Two-Legged Spacer Molecule for Alternate Layer LB Film Deposition with Optically Nonlinear Dyes

1992 ◽  
Vol 247 ◽  
Author(s):  
G. J. Ash Well ◽  
W. A. Crossland ◽  
P. J. Martin ◽  
P. A. Thompson ◽  
A. T. Hewson ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Second Harmonic ◽  
Film Deposition ◽  
Nonlinear Optical Susceptibility ◽  
Langmuir Blodgett ◽  
Lb Film ◽  
Active Layers ◽  
Optical Susceptibility ◽  
Langmuir Blodgett Films ◽  
Alternate Layer

ABSTRACTSecond harmonic generation from Langmuir-Blodgett films of E-N-octadecyl-4-(2-(4-dimethylaminophenyl)ethenyl)pyridinium iodide (a hemicyanine) interleaved with 4, 4'-dioctadecyl-3, 5, 3', 5'-tetramethyldipyrrylmethene hydrobromide (spacer) increases quadratically with the number of active layers, the second-order nonlinear optical susceptibility of film structures comprising from 1 to 150 bilayers being 70 pm/V. The synthesis and nonlinear optical properties are reported.

Synthesis, Spectroscopic Characterization and Thin Film Deposition of Three Novel Amphiphilic Porphyrins

1999 ◽  
Vol 03 (07) ◽  
pp. 569-584 ◽  
Author(s):  
COLIN L. HONEYBOURNE ◽  
KEVIN J. BARRELL
Keyword(s):  
Methyl Esters ◽  
Action Spectrum ◽  
Spectroscopic Characterization ◽  
Thin Film Deposition ◽  
Poor Quality ◽  
Film Deposition ◽  
Langmuir Films ◽  
Langmuir Blodgett ◽  
Lb Film ◽  
Cadmium Stearate

The synthesis of three novel porphyrins (that are models for mesoporphyrin) requires the synthesis of eight new pyrroles, one new alkyl-3-oxohexanoate and two new dipyrromethanes. The new porphyrin free bases have hydrophobic substitution patterns different from that in mesoporphyrin. We are seeking amphilic porphyrins that will form Langmuir–Blodgett (LB) multilayers without recourse to either long-chain alkyl substituents or fatty acid additives. In this way the influence of the conjugated tetrapyrrole unit on the properties of the multilayer films can be maximized. We report multilayer deposition for porphyrins having the following substituents: CH 3, C 2 H 5, n- C 3 H 7, ( CH 2)2 COOMe ; no additives such as stearic acid, cadmium stearate or mesitylene are required, Y-type deposition being exhibited by the simply substituted pure methyl esters. The variations in proton NMR chemical shift with concentration are reported and the action spectrum of an LB film of a porphyrinato- Zn (II) complex is described. Our observations and conclusions are in sharp (and optimistic) contrast with those of H. Chou et al. (J. Phys. Chem. 98, 383 (1994)), who found that in the absence of steric constraints from bulky aliphatic chains the Langmuir films are so rigid that either no multilayers or multilayers of poor quality are given. We obtain good-quality multilayers (60 layers) for porphyrins bearing eight small substituents.

Interactions at the Molecular Level between Biphosphine Ruthenium Complexes and Stearic Acid in Langmuir and Langmuir−Blodgett Films

2002 ◽  
Vol 106 (29) ◽  
pp. 7272-7277 ◽  
Author(s):  
Marystela Ferreira ◽  
Karen Wohnrath ◽  
Antonio Riul, ◽  
José A. Giacometti ◽  
Osvaldo N. Oliveira
Keyword(s):  
Stearic Acid ◽  
Molecular Level ◽  
Ruthenium Complexes ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films

Improved Second Harmonic Generation from Langmuir-Blodgett Films of an Azacrown Ether Fullerene Derivative

1994 ◽  
Vol 349 ◽  
Author(s):  
David A. Leigh ◽  
Frances Wade ◽  
Terry A. King ◽  
David West ◽  
Gurmit S. Bahra
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Fullerene Derivative ◽  
Azacrown Ether ◽  
Langmuir Blodgett ◽  
Lb Film ◽  
Film Forming ◽  
Langmuir Blodgett Films ◽  
Order Susceptibility

The amphiphilic fullerene derivative (1-aza-18-crown-6)-hydrofullerene-60 (C60-1A18C6, 1) exhibits improved Langmuir and Langmuir-Blodgett (LB) film forming properties and the resulting LB films exhibit a nonlinear second order susceptibility, X(2)pp of 3.2 pm/V, the highest yet reported for a fullerene or fullerene derivative.

From Langmuir-Blodgett Films to Electroluminescent Devices with an Amphiphilic Phenyl-Ethynylene Oligomer

1999 ◽  
Vol 598 ◽  
Author(s):  
E. Arias-Marin ◽  
J.C. Arnault ◽  
T. Maillou ◽  
D. Guillon ◽  
J. Le Moigne ◽  
...  
Keyword(s):  
Photon Emission ◽  
Layer By Layer ◽  
Step Method ◽  
Langmuir Blodgett ◽  
Lb Film ◽  
Amphiphilic Molecules ◽  
Rigid Rods ◽  
Layer Deposition ◽  
Langmuir Blodgett Films ◽  
Deposited Film

ABSTRACTNew rigid rods amphiphilic molecules based on phenyl ethynylenes oligomers with hydrophilic side chains were synthesized by step by step method. The two most interesting products, the pentamer and the heptamer are enough amphiphilic to give stable Langmuir films that are able to be deposited as LB film on substrates as hydro-philic glass, ITO or hydrophilic silicon. A good transfer ratio of 1 is observed only by lifting, which suggests a Z type deposited film. A multilayer deposition can be carried out to 36 layers. The well structured films of 3.7 nm thick which are observed by X ray reflectivity suggest a rearragement in Y–type bilayer. By AFM, the observed irregular surface with steps of 3.7 and 1.8 nm high or multiples is coherent with a self-rearrangement of the single deposited layer to a double layer during the drying phase. The heptamer and pentamer show large stokes-shifts with a high photoluminescence emission peak at 516 and 504 nm respectively. LED properties were demonstrated using the ITO/oligoPY/ LiF-Al sandwich yielding photon emission at 516 nm for the heptamer. The electroluminescent device yields in the range of 10−3%. The demonstration of electroluminescence in a LB film of molecules aligned parallel to the substrate is very interesting because it confirms the possibility to tailor conduction and emission properties of the devices using a layer by layer deposition technique.

Molecules for Langmuir—Blodgett film formation

1990 ◽  
Vol 330 (1610) ◽  
pp. 141-152 ◽  
Keyword(s):  
Molecular Electronics ◽  
Water Surface ◽  
Film Formation ◽  
Blodgett Film ◽  
Especial Reference ◽  
Langmuir Blodgett ◽  
Hydrophobic Character ◽  
Lb Film ◽  
Potential Applications ◽  
Langmuir Blodgett Film

Molecules with an appropriate balance between hydrophilic and hydrophobic character may be spread as monolayers on the water surface. Under appropriate conditions these monolayers may be built up onto a substrate as Langmuir-Blodgett (IB) films. This paper reviews the types of molecule that are known to give good LB film formation, with especial reference' to potential applications in molecular electronics.

scholarly journals Локализация экситона Ванье-Мотта на органополупроводниковом интерфейсе ленгмюровская пленка / CdS"

2019 ◽  
Vol 61 (7) ◽  
pp. 1362
Author(s):  
К.А. Королькова ◽  
В.Р. Новак ◽  
А.В. Селькин
Keyword(s):  
Spatial Dispersion ◽  
Crystal Surface ◽  
Exciton State ◽  
Film Deposition ◽  
Dead Layer ◽  
Organic Film ◽  
Langmuir Blodgett ◽  
Semiconductor Structures ◽  
Dispersion Effects ◽  
Langmuir Blodgett Films

Low temperature (T=2 K) optical reflection spectra have been studied for the organic-semiconductor structures prepared by deposition of Langmuir-Blodgett films on CdS surface. The spectra are measured in the resonant spectral range of the exciton state in CdS. Theoretical analysis of the spectra is carried out with an account of the spatial dispersion effects and the exciton-free surface “dead” layer. The conclusion has been drawn of the interface localization of the Wannier-Mott exciton due to organic film deposition on the crystal surface.

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