Electroluminescence Devices and Models

The other way to produce EL devices is based on a pin junction [47]. A pin junction with conjugated polymers was realized by electrochemical doping of the 

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Since the appearance of the redox [ii, iii] and conducting [iv] polymer-modified electrodes much effort has been made concerning the development and characterization of electrodes modified with electroactive polymeric materials, as well as their application in various fields such as -> sensors, actuators, ion exchangers, -> batteries, -> supercapacitors, -> photovoltaic devices, -> corrosion protection, -> electrocatalysis, -> elec-trochromic devices, electroluminescent devices (- electroluminescence) [i, v-viii]. See also -> electrochemically stimulated conformational relaxation (ESCR) model, and -> surface-modified electrodes. 

Ishii, H., K. Sugiyama, D. Yoshimura, E. Ito, Y. Ouchi, and K. Seki (1998). Energy-level alignment at model interfaces of organic electroluminescent devices studied by UV photoemission Trend in the deviation from the traditional way of estimating the interfacial electronic structnres. IEEE J. Select. Topics Quant. Chem. 4, 24-33. 

In the beginning of thel970, with solely nematic liquid crystals in use, the twisted nematic TN-LCD became mainstream for LCDs in electronic watches and calculators. The multiplexed LCD incorporates capacitors in their matrix circuits which led to crosstalk between the matrix elements. Therefore the amplitude selection method was developed to create a uniform bias voltage to control the crosstalk such as 3-to-l or 2-to-l amplitude selection. This model was known as the matrix addressing technology of inorganic electroluminescent devices. In order to apply this to TN-LCDs, the two next characteristics have to be considered. 

Oligothiophenes with well defined structures have recently received a great deal of attentions not only as a model eompoimds for conducting polymers, but also as anew class of functional r-electron systems [153], Since the initial discovery of organic compounds showing metallic conductivity, for which 2000 Nobel prize in chemistry was awarded [154-156], oligo- and polythiophenes have attracted much attention as advanced molecules with practical use in electronic devices [157-160] and their potential application in field-effect transistors [161], photovoltaic devices [162] and organic electroluminescent devices [163],... 

Besides the value of LB-films as model systems in fundamental research there are a number of potential applications for these layers. The incorporation of LB monolayers and multilayers into both metal/LB-film/metal and metal/LB-film/semiconductor (MIS) devices has recently been attracting considerable attention [237]. Structures in the first category may find application as the basis for simple photovoltaic cells or switches. When deposited onto semiconducting substrates, the fine control of the LB layer thickness permits the optimization of the efficiency of both photovoltaic and electroluminescent structures. Thicker films can be used to control the surface conductivity of a variety of semiconductors and as the basis for a field effect transistor. The three particular examples presented in this section should serve to indicate the usefulness of monomolecular insulating films in the field of microelectronics. 

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