PHOTOBRIGHTENING AND PHOTODARKENING IN CdSe NANOCRYSTAL/POLYMER THIN FILMS

2002 ◽  
Vol 01 (05n06) ◽  
pp. 641-644 ◽  
Author(s):  
HARUMI ASAMI ◽  
ITARU KAMIYA ◽  
MASAHIKO HARA
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Polymer Thin Films ◽  
Side Chain ◽  
Cdse Nanocrystals ◽  
Photoluminescence Intensity

The change in the photoluminescence intensity of CdSe nanocrystal/polymer thin films with duration of illumination is investigated. The choice of polymer has an influence on photobrightening and photodarkening. In particular, photodarkening in CdSe nanocrystal/poly(vinyl carbazole) thin film occurs immediately upon illumination, in contrast to the slow changes observed with polystyrene and poly(2-vinylpridine). We discuss the mechanisms of this phenomenon in comparison with interaction between surface of CdSe nanocrystals and polymer side chain.

scholarly journals Micro-supercapacitors based on oriented coordination polymer thin films for AC line-filtering

RSC Advances ◽  
2018 ◽  
Vol 8 (53) ◽  
pp. 30624-30628 ◽  
Author(s):  
Weiwei Hua ◽  
Jingwei Xiu ◽  
Fei Xiu ◽  
Zepu Zhang ◽  
Juqing Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Coordination Polymer ◽  
Polymer Thin Films ◽  
Polymer Thin Film ◽  
Electrode Fabrication ◽  
Thin Film Electrodes ◽  
Substrate Independent

Micro-supercapacitors exhibiting excellent AC line-filtering with oriented coordination polymer thin-film electrodes are fabricated based on a substrate-independent electrode fabrication strategy.

Alternation of Side-Chain Mesogen Orientation Caused by the Backbone Structure in Liquid-Crystalline Polymer Thin Films

Langmuir ◽  
2015 ◽  
Vol 31 (42) ◽  
pp. 11379-11383 ◽  
Author(s):  
Daisuke Tanaka ◽  
Yuki Nagashima ◽  
Mitsuo Hara ◽  
Shusaku Nagano ◽  
Takahiro Seki
Keyword(s):  
Thin Films ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Polymer Thin Films ◽  
Crystalline Polymer ◽  
Side Chain ◽  
Backbone Structure

Preparation and characterization of side-chain liquid crystalline polymer thin films aligned on PTFE friction-transferred layers

Polymer ◽  
1998 ◽  
Vol 39 (15) ◽  
pp. 3545-3550 ◽  
Author(s):  
J.C. Wittmann ◽  
S. Meyer ◽  
P. Damman ◽  
M. Dosière ◽  
H-W. Schmidt
Keyword(s):  
Thin Films ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Polymer Thin Films ◽  
Crystalline Polymer ◽  
Side Chain

GaAs Surface Passivation by InGaP Thin Film

1991 ◽  
Vol 240 ◽  
Author(s):  
Fumiaki Hyuga ◽  
Tatsuo Aoki ◽  
Suehiro Sugitani ◽  
Kazuyoshi Asai ◽  
Yoshihiro Imamura
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Carrier Concentration ◽  
High Performance ◽  
Surface Passivation ◽  
Wide Bandgap ◽  
Gaas Surface ◽  
Photoluminescence Intensity ◽  
Barrier Heights ◽  
Wide Bandgap Materials

ABSTRACTInGaP thin films are evaluated as wide-bandgap materials for GaAs surface passivation. A 200-Å InGaP thin film increases GaAs photoluminescence intensity 25-fold and enables Schottky barrier heights of more than 0.6 eV on n-type GaAs layers with a carrier concentration of 3×1018 /cm3. These effects persist after annealing at 800 °C for 10 min. InGaP thin films are thus suitable as surface passivation films for high-performance GaAs-MESFETs.

Thickness Dependent on Energy Band Gap and Electrical Conductivity of Undoped Conjugated Polymer Thin Films

2016 ◽  
Vol 846 ◽  
pp. 620-625 ◽  
Author(s):  
Hamizah Nadia Alias@Yusof ◽  
Hasiah Salleh ◽  
Mohd Ikmar Nizam Mohamad Isa
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Conductivity ◽  
Band Gap ◽  
Energy Band ◽  
Conjugated Polymer ◽  
Polymer Thin Films ◽  
Energy Band Gap ◽  
Lower Energy Band ◽  
Ito Glass

Conjugated polymers have been widely used for electronic purpose applications due to their numerous advantages. This has led many researches to pay their major attention in studying on characteristics of conjugated polymer thin films. The purpose of this study was to investigate the effect of undoped conjugated polymer thin films on their optical and electrical properties. Poly(3-thiophene acetic acid), Polypyrrole and Polythiophene thin film was fabricated on ITO glass substrate by using EIS. Film thickness, energy band gap and electrical conductivity of thin films were characterized by using profilometer, ultraviolet-visible spectrometer and four point probe method respectively. The thickness of each thin film varied between 50.534 nm to 97.03 nm. The result has shown that thicker film has lower energy band gap compared to the thinner one. However the electrical conductivity showed an opposite behavior.

scholarly journals In-Situ Neutron Reflectometry on Polymer Thin Films in Different Environments

2014 ◽  
Vol 70 (a1) ◽  
pp. C880-C880
Author(s):  
Naoya Torikai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Change ◽  
Block Copolymer ◽  
Polymer Thin Films ◽  
Neutron Reflectometry ◽  
Proton Accelerator ◽  
Original Structure ◽  
Material Interfaces

Neutron reflectometry is indispensable for the studies on material interfaces and thin films, since it can probe the interfaces non-destructively with a quite high depth resolution. Here, the interfacial structures of polymer thin films in different environments: hot and wet, were examined by means of in-situ neutron reflectometry. The neutron reflectivity measurements were performed on a time-of-flight reflectometer SOFIA [1, 2] at the Japan Proton Accelerator Research Complex (J-PARC). The depth distribution of components was investigated for binary blend thin films of polystyrenes with different molecular weights to clarify the mechanism of de-wetting suppression effect by blending a small amount of the longer homologue. It was found by static measurements that the longer chains deplete from the air surface of the film, while they slightly localize at the interface with the substrate. The time evolution of the component distribution was also examined by in-situ measurements above the glass transition temperature in a vacuum. The structural change of lamellarly-ordered styrene-2-vinylpyridine (PS-P2VP) diblock copolymer thin film in contact with solvent was explored by in-situ neutron reflectometry with a conventional solid/liquid cell. During the block copolymer thin film was in contact with methanol, which is selective for P2VP, some of methanol penetrated into the film causing the structural change. However, the original structure was almost recovered after drying, though annealing effect was slightly observed. When toluene was made contact, which is selective for PS, the block copolymer thin film was immediately dissolved into, and never recovered.

scholarly journals Dynamics and Structure Formation of Confined Polymer Thin Films Supported on Solid Substrates

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1621
Author(s):  
Mujib Ur Rahman ◽  
Yonghao Xi ◽  
Haipeng Li ◽  
Fei Chen ◽  
Dongjie Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Thickness ◽  
Effective Viscosity ◽  
Polymer Thin Films ◽  
Polymer Substrate ◽  
Native Oxide Layer ◽  
Si Substrates ◽  
Substrate Interaction ◽  
Residual Film

The stability/instability behavior of polystyrene (PS) films with tunable thickness ranging from higher as-cast to lower residual made on Si substrates with and without native oxide layer was studied in this paper. For further extraction of residual PS thin film (hresi) and to investigate the polymer–substrate interaction, Guiselin’s method was used by decomposing the polymer thin films in different solvents. The solvents for removing loosely adsorbed chains and extracting the strongly adsorbed irreversible chains were selected based on their relative desorption energy difference with polymer. The PS thin films rinsed in chloroform with higher polarity than that of toluene showed a higher decrease in the residual film thickness but exhibited earlier growth of holes and dewetting in the film. The un-annealed samples with a higher oxide film thickness showed a higher decrease in the PS residual film thickness. The effective viscosity of PS thin films spin-coated on H-Si substrates increased because of more resistance to flow dynamics due to the stronger polymer–substrate interaction as compared to that of Si-SiOx substrates. By decreasing the film thickness, the overall effective mobility of the film increased and led to the decrease in the effective viscosity, with matching results of the film morphology from atomic force microscopy (AFM). The polymer film maintained low viscosity until a certain period of time, whereupon further annealing occurred, and the formation of holes in the film grew, which ultimately dewetted the film. The residual film decrement, growth of holes in the film, and dewetting of the polymer-confined thin film showed dependence on the effective viscosity, the strength of solvent used, and various involved interactions on the surface of substrates.

Side Chain Influence on the Mechanical Properties and Water Uptake of Confined Comb-Shaped Cationic Polymer Thin Films

2016 ◽  
Vol 217 (21) ◽  
pp. 2442-2451 ◽  
Author(s):  
Douglas I. Kushner ◽  
Liang Zhu ◽  
Ahmet Kusoglu ◽  
Michael A. Hickner
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Water Uptake ◽  
Polymer Thin Films ◽  
Cationic Polymer ◽  
Side Chain

Effect of solvent vapour annealing on polymer thin films and application in nonlinear optical fields

2014 ◽  
Vol 2 (41) ◽  
pp. 8662-8666 ◽  
Author(s):  
Shiwei Wang ◽  
Wanli Su ◽  
Yunhui Li ◽  
Rongwei Zhang ◽  
Xibin Wang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Weight ◽  
Nonlinear Optical ◽  
Polymer Thin Films ◽  
Low Molecular Weight ◽  
Optical Fields ◽  
Polymer Thin Film ◽  
Solvent Vapour ◽  
Effect Of Solvent

Solvent vapour annealed (SVA) technique was successfully used in controlling the morphology of polymer thin film blending with low molecular weight chromophoric (LMWC) molecules.

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