Poly(p-phenylenevinylene) by chemical vapor deposition: synthesis, structural evaluation, glass transition, electroluminescence, and photoluminescence

Schäfer, Oliver; Greiner, Andreas; Pommerehne, J.; Guss, W.; Vestweber, H.; Tak, Hyunwoo; Bäßler, H.; Schmidt, Claudia; Lüssem, G.; Schartel, Bernhard; Stümpften, V.; Wendorff, Joachim H.; Spiegel, Stefan; Möller, Claudia; Spiess, Hans Wolfgang

doi:10.1016/s0379-6779(97)80001-x

Cited by 125 publications

(54 citation statements)

References 27 publications

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“…Thus, chemical vapor deposition (CVD), which provides a clean environment as a solvent-free and low temperature process that is well suited to sequential deposition [32], has been employed to prepare pinhole-free films of PPV that are amorphous or nanocrystalline and which show a glass transition [33]. The sol-gel technique [34] has been applied to the preparation of PPV/sol-gel composites [35] in order to improve the lifetime and efficiency and to tune the emitting high frequency of devices.…”

Section: Electroluminescence In Conjugated Polymeric Systemsmentioning

confidence: 99%

“…Although several synthetic routes are available for its production [94,95], for the manufacture of the original device Leising and co-workers used an elegant route via a precursor polymer by following the procedure previously established by ICI workers (Scheme 6) [96]. Monomer 35, obtained by esterification of cyclohexadienediol 34, undergoes free radical polymerization to give a processable precursor polymer 36, which is converted to PPP (33) by an elimination process upon heating.…”

Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

See 1 more Smart Citation

The chemistry of electroluminescent organic materials

Segura¹

1998

Acta Polym.

287

200

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Electroluminescence has been a subject of interest for several decades because of its many applications in areas such as telecommunications or information displays. Light‐emitting diodes using p‐n junctions of inorganic semiconductors have dominated the field in the last twenty years; however, efficient blue emission has only recently been achieved and inorganic semiconductors are difficult to form over large areas, making the process uneconomic. During the last decade, an explosive growth of activity in the area of organic electroluminescence has occurred in both academia and industry, stimulated by the promise of light‐emitting plastics for the fabrication of large, flexible, inexpensive and efficient screens to be used in different applications. Thus, a substantial amount of research is presently directed towards color control and improvement of manufacturability and reliability of devices in order to make their commercialization viable. A great deal of work has been carried out by physicists and materials scientists concerned with the preparation of different device structures and with the use of different techniques for device manufacture. However, all this work would not be possible without the continuous efforts of synthetic chemists to prepare materials with enhanced luminescent properties and processabilities. This article provides a review of the main types of organic materials that have been used in the fabrica‐tion of light‐emitting diodes either as emitting materials or as charge‐transport layers. Special attention will be paid to the different synthetic strategies that have been followed in order to tune the color of the emission, to increase stability of materials and to enhance their processabilities.

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Section: Electroluminescence In Conjugated Polymeric Systemsmentioning

confidence: 99%

Section: Modulation Of Electronic Properties Of Conjugated Polymers Tmentioning

confidence: 99%

The chemistry of electroluminescent organic materials

Segura¹

1998

Acta Polym.

287

200

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“…PPX was synthesized following the procedure of Gorham [3] using a pyrolysis apparatus as presented previously [7].…”

Section: Synthesis Of Ppxmentioning

confidence: 99%

Structural analysis of PPX prepared by vapor phase pyrolysis of [2.2]paracyclophane

et al. 1998

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Poly(p‐xylylene) (PPX) was prepared by vapor phase pyrolysis of [2.2]paracyclophane following the procedure of Gorham. PPX was obtained in different crystalline modifications by dry annealing, dissolution and reprecipitation under different conditions. These samples were analyzed by WAXS and 13C CP‐MAS NMR spectroscopy. Clear evidence was found that the presence of different crystalline modifications is responsible for the unexpected 13C CP‐MAS NMR spectrum as observed for as‐polymerized PPX. An attempt was made to explain the differences observed in the 13C CP‐MAS NMR spectra of different crystalline modifications by different chemical environments utilizing simulations of the crystal unit cells.

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“…After post-deposition annealing, the new peaks in Figure 6 at 16.8°2h and to a lesser extent 25.4°2h do not match literature values for PPV, however, they are indicative of the occurrence of significant crystallization. [22] Schafer et al observed very little crystallization below 200°C. The difference between the two studies might be the crystal structure of two films.…”

Section: Resultsmentioning

confidence: 97%

“…The difference between the two studies might be the crystal structure of two films. [22] Parylene is known to have an a-phase and a b-phase. The current study is more like the a-phase previously observed with poly(p-xylylene)).…”

Section: Resultsmentioning

confidence: 99%

Dehydrohalogenation in Alpha-Functionalized Poly-p-xylylenes

Carrow

Bakhru²,

Wang

et al. 2006

Chem. Vap. Deposition

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Poly(p-xylylene) or parylene has been around for more than a half a century. It is typically deposited by the Gorham method from [2.2] paracyclophane. However, another method is via alpha-derivatives of p-xylene. Both poly(a-bromo-p-xylylene) and poly(a-chloro-p-xylylene) have been successfully deposited by this route through predominately HBr or HCl dehydrohalogenation gas-phase reactions. In the study reported here we synthesize a,a,a-tribromo-p-xylene and a-bromo-a′,a′-dichlorop-xylene as CVD precursors to yield a,a-and a,a′-dihalogenated poly(p-xylylene)s to try to convert them, via post-deposition annealing, to poly(phenylene ethynylene) (PPE). PPE and its intermediate poly(phenylene vinylene) (PPV), have potentially better thermal and oxidative properties, and in addition they are both photoluminescent. The as-deposited and annealed thin films have been characterized by Rutherford backscattering spectrometry (RBS), infrared spectroscopy, and UV-vis spectrophotometry, and electrically tested by dielectric constant, bias-temperature stress (BTS), and leakage current. It is found that the thin films crystallizes concurrent with the formation of PPV and possibly converts to PPE but has much residual chlorine and bromine. However, PPV exhibits excellent stability in contact with copper and is more thermally stable than poly(p-xylylene).

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Poly(p-phenylenevinylene) by chemical vapor deposition: synthesis, structural evaluation, glass transition, electroluminescence, and photoluminescence

Cited by 125 publications

References 27 publications

The chemistry of electroluminescent organic materials

The chemistry of electroluminescent organic materials

Structural analysis of PPX prepared by vapor phase pyrolysis of [2.2]paracyclophane

Dehydrohalogenation in Alpha-Functionalized Poly-p-xylylenes

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