Organic devices

The device model describes transport in the organic device by the time-dependent continuity equation, with a drift-diffusion form for the current density, coupled to Poisson s equation. To be specific, consider single-carrier structures with holes as the dominant carrier type. In this case,... 

Coe, S. Woo, W.-K. Bawendi, M. B. Bulovic, V. 2002. Electroluminescence from single monolayers of nanocrystals in molecular organic devices. Nature 420 800-803. 

Future Generation Vapor-Deposited Organic Devices.553... 

The aim of this chapter is to give the reader a broad overview of the field of vapor-deposited small-molecule OLEDs. It is beyond the scope of this chapter to cover every aspect of these devices, however key references are given throughout the text for those readers who are interested in delving more deeply into this topic. Section 7.2 describes the key elements of a typical OLED. Alternative device architectures are also briefly described. Section 7.3 describes the typical fabrication methods and materials used in the construction of vapor-deposited OLEDs. Section 7.4 describes the physics of an OLED in addition to the improvement of the performance over time made through advances in device architectures and materials. Section 7.5 discusses OLED displays and Section 7.6 looks at the future exciting possibilities for the field of vapor-deposited organic devices. 

FUTURE GENERATION VAPOR-DEPOSITED ORGANIC DEVICES 7.6.1 Flexible Displays... 

Walzer K, Maennig B, Pfeiffer M, Leo K (2007) Highly efficient organic devices based on electrically doped transport layers. Chem Rev 107 1233... 

Maitani MM, Allara DL, Ohlberg DAA, Li Z, Williams RS, Stewart DR (2010) High integrity metal/organic device interfaces via low temperature buffer layer assisted metal atom nucleation. Appl Phys Lett 96(17) 173109-173113... 

In the last section, electron transfer between dendrimers in films was mentioned. This type of hopping is important in thin-film organic devices (see above). How do dendrimers behave in solution Are the paradigms the same Actually, they are not. 

The primary focus of the book is on reaction mechanisms, not only because knowledge of mechanism is essential to understanding chemical processes but also because theories about reaction mechanisms can explain diverse chemical phenomena in terms of a relatively small number of general principles. It is this latter capability of mechanistic theory which makes it important as an organizing device for the subject of organic chemistry as a whole. 

The organic NLO materials reported here have good processabilities, so they have an advantage for developing new nonlinear optical organic devices. 

Some improvement was observed with pentacene deposited on top of silane layers, but it was also observed that the silane deposition is not easy to control, and side-reactions often result in rough layers with considerable unreacted content remaining. An alternative approach relies on application of self-assembled monolayers which mimic vapor-deposited silanes [32, 33] on the dielectric interface of the organic devices. Figure 2.6 shows an overview of the different surface-treatment application methods discussed in this section. 

Besides chemical synthesis, purity of the employed chemicals is essential for the organic device performance desired. Small-molecule materials, which are only poorly soluble, are usually purified by repeated train sublimation, which results in substantial losses of material and additional purification costs. These material requirements are almost identical for OVPD and VTE. Because of the different deposition processes, the thermal stress on the organic materials is different in OVPD and in VTE. OVPD operates under steady-state temperature conditions without ramping of the evaporation temperature during processing, as is typically applied in VTE. Depending on the vapor pressure of the organic materials used and the... 

The number of papers which have recently been published on the organic materials and devices has become very large. We have included some 200 papers in the bibliography, which are most relevant for the coherent description of recent developments. To make the bibliography more useful, titles of the most important papers have been included, and the subject matter is treated at an appropriate level for students as well as senior researchers interested in the design and modelling of the organic devices. 

Disordered physisorption—that is, random deposition of molecules from the vapor phase to a metal substrate—will usually yield random orientations and poor packing, while a preferential orientation of an asymmetric molecule may be needed for organic device performance. 

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