Voltage-Tunable Multicolor Electroluminescence from Single-Layer Polymer Blends and Bilayer Polymer Films

Author(s):  
Maksudul M. Alam ◽  
Christopher J. Tonzola ◽  
Yan Zhu ◽  
Samson A. Jenekhe
2001 ◽  
Vol 635 ◽  
Author(s):  
Donglu Shi ◽  
Zhou Yu ◽  
S. X. Wang ◽  
Wim J. van Ooij ◽  
L. M. Wang ◽  
...  

AbstractMulti-layer ultrathin polymer films have been deposited on the surfaces of nanoparticles of alumina using a plasma polymerization treatment. The nanoparticles ranged from 10-150 nm in spherical shapes. High-resolution transmission electron microscopy (HRTEM) experiments showed that an extremely thin film of the pyrrole layer (10-20 Å) was uniformly deposited on the surfaces of the nanoparticles. In particular, the particles of all sizes (10-150 nm) exhibited equally uniform ultrathin films indicating well-dispersed nanoparticles in the fluidized bed during the plasma treatment. After single layer coating, hexamethyldisiloxane (HMDSO) was coated again as a second layer onto the surface of pyrrole. Subsequently, a third layer of pyrrole was coated on the top of HMDSO film completing the multi-layer coating process. Time-of-Flight Secondary ion mass spectroscopy (TOFSIMS) experiments confirmed the deposition of these multi-layer thin films on the nanoparticles. The deposition mechanisms and the effects of plasma treatment parameters are discussed.


1999 ◽  
Vol 581 ◽  
Author(s):  
Ch. Brugger ◽  
S. Tasch ◽  
M. Lal ◽  
P.N. Prasad ◽  
G. Leising

ABSTRACTWe have investigated the photophysical properties of surface capped CdS and CdS:Mn nanoparticles in the form of spin coated thin films of the pure nanoparticles and nanoparticle -polymer blends. The organic capping reagent was p-thiocresol. Electroluminescence (EL) devices were fabricated and characterized by their current/voltage characteristics and EL emission performance. This is to our knowledge the first report on Mn doped CdS nanoparticles applied in EL devices with a single layer device structure (ITO/CdS:Mn/Al). Photoluminescence (PL) and PL excitation measurements were performed on CdS:Mn nanoparticles in pyridine dispersion and on thin films. The PL excitation spectrum shows a narrow peak at 390nm. Excitation at this wavelength yields a broad PL spectrum spanning from about 450 to 700nm, which is dominated by a strong emission band at 585nm. This emission is attributed to transitions involving Mn levels in previous works. The EL emission peak is shifted to the red compared to the PL emission spectra. The characteristics and performance of these new types of EL devices will be presented and discussed.


2010 ◽  
Vol 96 (21) ◽  
pp. 213301 ◽  
Author(s):  
Sergio Brovelli ◽  
Hao Guan ◽  
Gustaf Winroth ◽  
Oliver Fenwick ◽  
Francesco Di Stasio ◽  
...  

Author(s):  
P. H. Brodsky ◽  
G. G. Cocks ◽  
C. C Winding

Microscopical observations of films made up of two incompatible polymers may provide useful insights into the unusual properties of many polymer blends. In the present study an attempt has been made to determine the factors which control the sizes and shapes of the phases present in solution-cast, two-polymer films. The variables included the ratio of the two polymers, the concentration of the solution from which the films were prepared, and the type of solvent used.The polymers studied included poly(vinyl acetate), a copolymer containing 85% poly(vinyl chloride) and 15% poly(vinyl acetate), poly(methyl methacrylate, and polystyrene. These will be abbreviated PVAc, PVC copolymer, PMMA, and PS respectively. The solvents included methyl ethyl ketone (MEK), toluene, benzene, and chloroform and the solution concentrations were varied from 0.2 to 1.0 per cent solids by weight.


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