A new method for fabricating high performance polymeric thin films by chemical vapor polymerization

1996 ◽  
Vol 11 (7) ◽  
pp. 1842-1850 ◽  
Author(s):  
Justin F. Gaynor ◽  
J. Jay Senkevich ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
High Performance ◽  
Chemical Vapor ◽  
Polymeric Thin Films ◽  
Copolymer Films ◽  
Initiation Reaction ◽  
First Time ◽  
Rate Limiting ◽  
Vacuum Deposition Method ◽  
General Method

A vacuum deposition method is presented in which copolymer films are grown from a vinylic monomer chosen for desirable properties and paraxylylene. The concentration of paraxylylene in the final copolymer can be negligibly small if proper deposition conditions, presented here for the first time, are employed. Films of paraxylylene with N-phenyl maleimide deposited at 40 °C, for example, showed thermal stability and FTIR spectra nearly identical with homopolymers of poly(N-phenyl maleimide). Different rate-limiting steps are proposed to explain film composition; paraxylylene is under surface reaction control, while the comonomer obeys mass flow control. This results in a deposition environment extremely rich in comonomer. Growth rates and compositions were consistent with predictions. The initiation reaction did not appear different from homopolymerization of paraxylylene. The general method presented here allows fabrication of vapor-deposited thin films with properties limited primarily by the comonomer employed.

Synthesis of single-crystalline GeS nanoribbons for high sensitivity visible-light photodetectors

2015 ◽  
Vol 3 (31) ◽  
pp. 8074-8079 ◽  
Author(s):  
Changyong Lan ◽  
Chun Li ◽  
Yi Yin ◽  
Huayang Guo ◽  
Shuai Wang
Keyword(s):  
Visible Light ◽  
Vapor Deposition ◽  
High Performance ◽  
Incident Light ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Single Crystalline ◽  
Promising Application ◽  
Photo Detection ◽  
First Time

Single-crystalline GeS nanoribbons were synthesized by chemical vapor deposition for the first time. The nanoribbon photodetectors respond to the entire visible incident light with a response edge at around 750 nm and a high responsivity, indicating their promising application for high performance broadband visible-light photo-detection.

Studies in polymerization. I. A method for determining the velocity constants in polymerization reactions and its application to styrene

1948 ◽  
Vol 192 (1030) ◽  
pp. 309-328 ◽  
Keyword(s):  
Kinetic Scheme ◽  
Frequency Factor ◽  
Thermal Polymerization ◽  
Kinetic Chain ◽  
Rate Of Increase ◽  
Initiation Reaction ◽  
After Effect ◽  
Photochemical Initiation ◽  
First Time ◽  
General Method

A general method for determining the velocity constants of initiation, propagation, transfer and termination in polymerization reactions is described. The method depends essentially on the measurement of the rate of increase of viscosity for various rates of chain initiation. In the case of radical polymerizations photochemical initiation is most convenient. Measurement of the photochemical after-effect then gives four independent relations between the four velocity constants. The method has been tested by a detailed study of the thermal and photochemical polymerization of styrene. Velocity constants have been determined at 0 and 25° C, and the activation energies and frequency factors calculated. Results are given in tables 5 and 6. It is shown for the first time that chain transfer is important in the thermal polymerization of pure styrene, occurring 11 times per kinetic chain at 25° C. This result invalidates conclusions which previous workers have reached. Other rather unexpected results are that the initiation reaction has a much higher activation energy than has been generally supposed, and a normal frequency factor, while termination is activated. A detailed kinetic scheme is proposed which removes certain unjustifiable assumptions present in earlier ones. This is shown to be consistent with all the available evidence.

Interfacial Adhesion of Nanoporous Zeolite Thin Films

Materials ◽  
2004 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan
Keyword(s):  
Thin Films ◽  
Interfacial Adhesion ◽  
High Performance ◽  
Interfacial Strength ◽  
Synthesis Process ◽  
Seeded Growth ◽  
Thermal Methods ◽  
Laser Spallation ◽  
First Time ◽  
Low K

Nanoporous zeolite thin films are promising candidates as future low-k materials. During the integration with other semiconducting materials, the high stresses resulted from the synthesis process can cause the film to fracture or delaminate from the substrates. Evaluating the interfacial adhesion of zeolite thin films is very important in achieving high performance low-k materials. In this work, laser spallation technique is utilized to investigate the interfacial strength of zeolite thin films from three different synthesis processes. The preliminary results show that the fully crystalline zeolite thin films from hydro-thermal in-situ and seeded growth methods have a stronger interface than that from the spin-on process. Effort is also being made to compare the interfacial strength of the zeolite films between the two hydro-thermal methods. This is the first time that the interfacial strength of zeolite thin films is quantitatively evaluated. The results have great significance in the future applications of low-k zeolite thin films.

High-performance CuFe2O4 epitaxial thin films with enhanced ferromagnetic resonance properties

RSC Advances ◽  
2016 ◽  
Vol 6 (102) ◽  
pp. 100108-100114 ◽  
Author(s):  
Ruyi Zhang ◽  
Ming Liu ◽  
Lu Lu ◽  
Shao-Bo Mi ◽  
Chun-Lin Jia ◽  
...  
Keyword(s):  
Thin Films ◽  
Ferromagnetic Resonance ◽  
High Performance ◽  
Bulk Material ◽  
Epitaxial Films ◽  
Epitaxial Thin Films ◽  
Resonance Properties ◽  
First Time

CuFe2O4 epitaxial films with superior FMR properties compared with bulk material have been successfully fabricated for the first time.

X-Ray Photoemission Spectromicroscopy Of Gan And AIGan

1998 ◽  
Vol 512 ◽  
Author(s):  
G. F. Lorusso ◽  
H. Solak ◽  
F. Cerrina ◽  
J. H. Underwood ◽  
P. J. Batson ◽  
...  
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Sample Surface ◽  
Photoemission Spectroscopy ◽  
Chemical Inhomogeneity ◽  
X Ray ◽  
Spatially Resolved ◽  
First Time

ABSTRACTWe investigate here for the first time GaN and AIGaN films by using x-ray photoemission spectromicroscopy. As compared to conventional x-ray photoemission spectroscopy (XPS), spectromicroscopy can provide spatially resolved information on the chemical composition of the sample surface. The experimental results where obtained by using MAXIMUM, a scanning photoemission microscope installed on 12.0 undulator beamline at the Advanced Light Source (ALS), Berkelely, allowing for a spatial resolution of 100 nm. We investigate here GaN and AlGaN thin films grown on sapphire substrate by metalorganic chemical vapor deposition (MOCVD). The results clearly indicate the great potential of spectromicroscopy in investigating chemical inhomogeneity, inpurities and localization in GaN and AlGaN thin films.

CVD-grown copper tungstate thin films for solar water splitting

2018 ◽  
Vol 6 (22) ◽  
pp. 10206-10216 ◽  
Author(s):  
D. Peeters ◽  
O. Mendoza Reyes ◽  
L. Mai ◽  
A. Sadlo ◽  
S. Cwik ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Copper Oxide ◽  
Water Splitting ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
High Quality ◽  
Solar Water Splitting ◽  
Copper Tungstate ◽  
First Time

In this paper, a direct chemical vapor deposition (CVD) approach is applied for the first time to synthesize high quality copper oxide (CuO), copper tungstate (CuWO4) and tungsten oxide (WO3) on F:SnO2 (FTO) substrates for photocatalytic water splitting.

Highly Transparent and Conductive CdO Thin Films as Anodes for Organic Light-Emitting Diodes

2005 ◽  
Vol 871 ◽  
Author(s):  
Yu Yang ◽  
Qinglan Huang ◽  
Andrew W. Metz ◽  
Shu Jin ◽  
Jun Ni ◽  
...  
Keyword(s):  
Thin Films ◽  
Light Emitting Diodes ◽  
Chemical Vapor ◽  
Organic Light Emitting Diodes ◽  
Organic Chemical ◽  
Light Emitting ◽  
Organic Light ◽  
Metal Organic ◽  
Cdo Thin Films ◽  
First Time

AbstractIn this paper, CdO thin films are used for the first time as transparent anodes for organic light-emitting diodes (OLEDs). Highly conductive and transparent CdO thin films have been grown on glass and on single-crystal MgO(100) by low pressure metal-organic chemical vapor deposition (MOCVD) at 400°C, and were implemented in small-molecule OLED fabrication. Device response and applications potential have been investigated and compared with those of commercial ITO-based control devices. It is found that as-deposited CdO thin films are capable of injecting holes into such devices, rendering them promising anode materials for OLEDs. A maximum luminance of 32,000 cd/m2 and an external forward quantum efficiency of 1.4 %, with a turn-on voltage of 3.2 V are achieved on MgO(100)/CdO-based devices.

scholarly journals High-performance thin H:SiON OLED encapsulation layer deposited by PECVD at low temperature

RSC Advances ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Kyoung Woo Park ◽  
Seunghee Lee ◽  
Hyunkoo Lee ◽  
Yong-Hwan Cho ◽  
Yong Cheon Park ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
High Performance ◽  
Single Layer ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Layer Thin Film

High-performance H:SiON single layer thin film encapsulation (TFE) was deposited by plasma enhanced chemical vapor deposition (PECVD) method. To control the characteristics of the SiON thin films, hydrogen gas was introduced during PECVD process.

Growth and Characterization of Organic Polymeric Thin Films From Isopropanol by PECVD.

2009 ◽  
Vol 1242 ◽  
Author(s):  
J. O. Martínez-Gutiérrez ◽  
G. Romero-Paredes ◽  
R. Peña-Sierra ◽  
A. Ávila-García ◽  
G. Juárez-Díaz
Keyword(s):  
Thin Films ◽  
Visible Region ◽  
Chemical Vapor ◽  
Ammonium Hydroxide ◽  
Organic Thin Films ◽  
Optical Bandgap ◽  
Polymeric Thin Films ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTPolymerized organic thin films were synthesized on a variety of substrates by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique using isopropanol as precursor. Hydrogen peroxide, ammonium hydroxide, and iodine dissolved in isopropanol were used as dopants and chlorobenzene as copolymerization precursor. The structural, optical and electrical properties of the films were studied as functions of the dopant type and concentration.The polymeric films were characterized by variable angle ellipsometry (VAE), atomic force microscopy (AFM), Fourier Transform Infrared spectroscopy (FTIR), ultraviolet-visible transmission spectroscopy and photoluminescence. The electrical film behavior was explored by the four points probe method.The growth rate, refractive index, optical bandgap, chemical structure and resistivity of the films strongly depend on the concentration and type of dopant added. The AFM microphotographs showed smooth surfaces with RMS roughness less than 10 nm. The optical bandgap values of the films were in the range of 2.6 to 3.26 eV, the resistivity was in the order of 103 – 104 ohm-cm. The photoluminescence response of the polymerized films was obtained in the visible region, by exciting with a UV laser.

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