Organic Solid Solutions: Formation and Applications in Organic Light‐Emitting Diodes

Abstract

To enhance the performance of organic devices, doping and graded mixed‐layer structures, formed by co‐evaporation methods, have been extensively adopted in the formation of organic thin films. Among the criteria for selecting materials systems, much attention has been paid to the materials' energy‐band structure and carrier‐transport behavior. As a result, some other important characteristics may have been overlooked, such as material compatibility or solubility. In this paper, we propose a new doping method utilizing fused organic solid solutions (FOSSs) which are prepared via high‐pressure and high‐temperature processing. By preparing fused solid solutions of organic compounds, the stable materials systems can be selected for device fabrication. Furthermore, by using these FOSSs, doping concentration and uniformity can be precisely controlled using only one thermal source. As an example of application in organic thin films, high‐performance organic light‐emitting diodes with both single‐color and white‐light emission have been prepared using this new method. Compared to the traditional co‐evaporation method, a FOSS provides us with a more convenient way to optimize the doping system and fabricate relatively complicated organic devices.

Growth, morphology and structure of mixed pentacene films

“…[1][2][3][4] The benefits of doping organic materials for e.g. OLED applications, 12 and of mixing n and p-type semiconductors in ambipolar transistors 13,14 have also been reported, as well as more fundamental studies on the structure of functional blends. 15 P-terphenyl and pentacene have similar crystal structures with one monoclinic and the other triclinic respectively.…”

On the nature of bulk electrical relaxation in 4‑tricyanovinyl-N,N-diethylaniline (TCVA)

“…Organic compounds have been extensively investigated in the fabrication of various electronic and photonic devices in the last two decades [1]. Some of the advantages of organic materials include flexibility in the methods of synthesis, scope for altering the properties by functional substitution and inherently high nonlinearity [2].…”

Long‐Lifetime Polymer Light‐Emitting Electrochemical Cells

“…[4,[17][18][19] When two or more materials are used in a blend, the material compatibility or mutual solubility is one of the keys to high-performance devices, especially for long-time operation. [20,21] Therefore, the proper selection of organic material components is an important issue. We found that MATS shows excellent compatibility with superyellow.…”