Low field operation of hot electron light emitting devices: quasi-flat-band model

2004 ◽  
Vol 151 (6) ◽  
pp. 482-485 ◽  
Author(s):  
J.Y. Wah ◽  
N. Balkan
2000 ◽  
Vol 633 ◽  
Author(s):  
Alexander N. Obraztsov ◽  
Alexander P. Volkov

AbstractThe non-catalytical chemical vapor deposition (CVD) method was used to grow carbon thin film material consisting of plate-like nanosized graphite crystallites and multiwall carbon nanotubes with predominant orientation of both species by their crystallographic plane, corresponding to a graphite basal plane, along a normal to the film surface. A number of experimental techniques was used for examination and characterization of the film phase composition, morphology, and electron properties peculiarities. Low-field electron emission with highly density of emission sites and emission current was obtained for the film material and allow to demonstrate their applicability for sealed prototypes of light-emitting devices.


2002 ◽  
Vol 734 ◽  
Author(s):  
Ludmila Bakueva ◽  
Sergei Musikhin ◽  
Edward H. Sargent ◽  
Alexander Shik

ABSTRACTMost conducting polymers used for light-emitting devices have a small electron affinity, creating a high barrier for electron injection resulting in low injection efficiency. To improve injection characteristics, we fabricated and investigated multi-layer contacts with a tunneltransparent dielectric layer of nanometer thickness. Polymer layers were prepared by spin coating, and dielectric and metallic contact layers subsequently grown by vacuum deposition. Samples with such multi-layer cathodes demonstrated a current-voltage characteristic with negative differential resistance. At larger applied voltage, electroluminescence was observed with an efficiency larger than for a simple cathode of the same metal. We have developed a model to describe double injection through multi-layer contacts which explains these salient observed features. The increase in injection efficiency is caused by the voltage drop at the dielectric layer, shifting the metal Fermi level relative to the polymer molecular orbitals responsible for carrier transport. The negative differential resistance is explained by the strong dependence of dielectric tunnel transparency on voltage, a dependence which is qualitatively different for electrons and holes. Further flexibility in the functional characteristics of the injecting contacts is achieved through the use of an additional thin metallic layer playing the role of a base electrode, similar to hot-electron transistors with metallic base.


2017 ◽  
Vol 183 ◽  
pp. 26-31 ◽  
Author(s):  
Y. Berencén ◽  
B. Mundet ◽  
J.A. Rodríguez ◽  
J. Montserrat ◽  
C. Domínguez ◽  
...  

2001 ◽  
Vol 171 (8) ◽  
pp. 857 ◽  
Author(s):  
Igor L. Krestnikov ◽  
V.V. Lundin ◽  
A.V. Sakharov ◽  
D.A. Bedarev ◽  
E.E. Zavarin ◽  
...  

2019 ◽  
Author(s):  
Miguel Anaya ◽  
Kyle Frohna ◽  
Linsong Cui ◽  
Javad Shamsi ◽  
Sam Stranks

1997 ◽  
Author(s):  
Y. Z. Wang ◽  
D. D. Gebler ◽  
D. K. Fu ◽  
T. M. Swager ◽  
A. J. Epstein

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4230
Author(s):  
Andreas Windischbacher ◽  
Luca Steiner ◽  
Ritesh Haldar ◽  
Christof Wöll ◽  
Egbert Zojer ◽  
...  

In recent years, the photophysical properties of crystalline metal-organic frameworks (MOFs) have become increasingly relevant for their potential application in light-emitting devices, photovoltaics, nonlinear optics and sensing. The availability of high-quality experimental data for such systems makes them ideally suited for a validation of quantum mechanical simulations, aiming at an in-depth atomistic understanding of photophysical phenomena. Here we present a computational DFT study of the absorption and emission characteristics of a Zn-based surface-anchored metal-organic framework (Zn-SURMOF-2) containing anthracenedibenzoic acid (ADB) as linker. Combining band-structure and cluster-based simulations on ADB chromophores in various conformations and aggregation states, we are able to provide a detailed explanation of the experimentally observed photophysical properties of Zn-ADB SURMOF-2: The unexpected (weak) red-shift of the absorption maxima upon incorporating ADB chromophores into SURMOF-2 can be explained by a combination of excitonic coupling effects with conformational changes of the chromophores already in their ground state. As far as the unusually large red-shift of the emission of Zn-ADB SURMOF-2 is concerned, based on our simulations, we attribute it to a modification of the exciton coupling compared to conventional H-aggregates, which results from a relative slip of the centers of neighboring chromophores upon incorporation in Zn-ADB SURMOF-2.


2019 ◽  
Vol 723 ◽  
pp. 33-38 ◽  
Author(s):  
Minhuan Wang ◽  
Yulin Feng ◽  
Qingshun Dong ◽  
Jiming Bian ◽  
Chen Wang ◽  
...  

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