Surface-Induced Parallel Alignment of Liquid Crystals by Linearly Polymerized Photopolymers

Schadt, M.; Schmitt, K.; Kozinkov, Vladimir; Chigrinov, Vladimir G.

doi:10.1143/jjap.31.2155

Cited by 1,090 publications

(667 citation statements)

References 16 publications

Supporting

Mentioning

646

Contrasting

Unclassified

Order By: Relevance

“…The molecules tend to align parallel with the micro-slits, suppressing azimuthal movement of the LC molecules [48,49]. Photo-alignment and reactive mesogens are also being developed to induce a pre-tilt angle [50,51].…”

Section: Response Timementioning

confidence: 99%

See 1 more Smart Citation

Technical evolution of liquid crystal displays

2009

View full text Add to dashboard Cite

I n 1888, more than a century ago, the Austrian botanist FriedrichReinitzer discovered an intermediate state of matter between isotropic liquid and lattice-structured crystal [1][2][3]. Th is state, later termed liquid crystal (LC), remained merely a novelty for many years until suitable applications for the technology began to become apparent. From the late 1960s, following the realization that various display applications were possible, the popularity of liquid crystal as a research fi eld expanded rapidly, attracting the interest of many scientists who made fundamental contributions to the technologies that have led to the spectacular success of liquid crystal displays (LCDs) [3][4][5][6][7][8][9][10][11][12][13]. Th e development of the twisted nematic (TN) [4] and supertwisted nematic (STN) [5] cell confi gurations, along with the necessary manufacturing technologies [6][7][8][9], resulted in the birth of the LCD industry in the late 1970s and early 1980s. The subsequent development of thin-film transistor (TFT) technology provided a further boost to the industry in the late 1980s [14,15]. Th e boom was signifi cantly supported by the advancement of material technologies such as the highly reliable manufacturing of liquid crystal base materials, and the development of polymers for the alignment layer, color fi lter materials, and sheet-type polarizers formed from the poly(vinyl alcohol)-iodine complex.In the 1990s, LCDs occupied an important position in the display market primarily through notebook applications, although the cathode ray tube (CRT) continued to dominate the desktop monitor and television markets. Th e plasma display panel (PDP), which appeared in the commercial market in 1997, pioneered the large-area fl at panel display market. It was widely predicted at the time that PDPs would maintain the lead in the large-area display market and that LCDs in small-display information technology (IT) applications would soon be replaced by new technologies such as displays based on organic light-emitting diodes (OLEDs) [16,17]. Such predictions were based on the belief that the LCD technology suff ered from serious limitations in terms of both off -axis image quality and moving picture quality, and also that it had proved diffi cult to obtain reasonable manufacturing yields of large-area TFT panels. However, these predictions, as we now know, turned out to be incorrect. Th e application of LCDs has expanded rapidly in recent years from purely information technology (IT) applications to the television and mobile display markets, and now even to very-large-area digital information displays (DIDs).Interestingly, while LCDs penetrated the traditional territories of other display technologies including CRTs and PDPs, attracting inevitable and heavy competition from these technologies, the most critical competitors were in fact alternative LCD technologies. A range of LCD modes and technologies are now applied in the same areas of application and are compared directly with one another in the market. In applicat...

show abstract

Section: Response Timementioning

confidence: 99%

“…A small number of reactive mesogen materials have been developed to date. Photo-alignment technology, developed to improve transmittance, is a major recent achievement that has been applied in a small number of commercial products [50,51].…”

Section: Review Articlementioning

confidence: 99%

Technical evolution of liquid crystal displays

2009

View full text Add to dashboard Cite

show abstract

“…Although rubbing is a simple and inexpensive method, it has many intrinsic drawbacks such as generation of electrostatic charges, contamination from rubbing debris and high temperatures (up to ca 250 1C). As alternatives to the rubbing process, noncontact methods such as photo-alignment [2][3][4][5] and ion-beam irradiation 6 have been used but they also have critical drawbacks associated with controlling the orientation of photoswitchs on the surface and low anchoring energies. 7 Indium-tin oxide (ITO) has been widely used as an electrode for LC display because of its low electrical resistance and high transmittance in the visible range of the optical spectrum.…”

Section: Introductionmentioning

confidence: 99%

Bifunctional ITO layer with a high resolution, surface nano-pattern for alignment and switching of LCs in device applications

et al. 2012

View full text Add to dashboard Cite

We describe a novel method for liquid crystal (LC) alignment using nano-patterns of electrically conductive indium-tin oxide (ITO) layers with high resolution (cao 20 nm) and high aspect ratio (ca 10), fabricated based on the secondary sputtering phenomenon. The ITO pattern developed in this manner not only provides high anchoring energy comparable to that of rubbed polyimides, but also maintains its low resistivity as an electrode. As a result, the patterned ITO can function as an electrode and alignment layer at the same time, which facilitates successful fabrication of bifunctional conductive alignment layer for LC devices. The LC cells fabricated using patterned ITO substrates show highly stable alignment of LCs over large area and good electro-optical responses. Moreover, systematic approach made by the precise control of pattern dimensions allows us to estimate a critical anchoring energy required for an effective LC alignment based on Berreman's theory.

show abstract

“…Orientation of liquid crystals (LCs) on various surfaces has been actively investigating in the last decades [1][2][3][4][5] due to necessity of perfectly aligned panels in LCD industry and because of serious fundamental aspects of LC various an− choring phenomena. One of advanced orientation techni− ques implies photosensitive polymer layers irradiated with polarised UV−light [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

“…One of advanced orientation techni− ques implies photosensitive polymer layers irradiated with polarised UV−light [3][4][5]. Polarised UV−exposure induces anisotropy in polymer layers leading to formation of easy orientation axis on irradiated polymer surface [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Exposure and temperature dependences of contact angle of liquid crystals on photoaligning surface

Gvozdovskyy¹,

Kurioz²,

Reznikov³

2009

Opto-Electronics Review

View full text Add to dashboard Cite

We report on first studies of wetting of liquid crystal on photoaligning surface. We observed strong light-induced variations of a contact angle of a liquid LC 5CB on a photoaligning surface of fluoro-polyvinyl-cinnamate (PVCN-F) and we connected these variations with changes of PVCN-F polarity. We also present drastic changes of the contact angle of a nematic liquid crystal (MLC-6080) on the PVCN-F surface in a vicinity of temperature anchoring transition of liquid crystal from homeotropic orientation to planar one. We did not find any peculiarities in temperature dependence of the contact angle of isotropic liquid (glycerol) on PVCN-F and of nematic liquid crystal on pure glass in the same temperature range. It allows us to suggest that rearrangement of LC molecules and flexible fragments in the LC-polymer interface are responsible for the change of surface tensions both of LC and polymer and the observed jump of the contact angle.

show abstract

Surface-Induced Parallel Alignment of Liquid Crystals by Linearly Polymerized Photopolymers

Cited by 1,090 publications

References 16 publications

Technical evolution of liquid crystal displays

Technical evolution of liquid crystal displays

Bifunctional ITO layer with a high resolution, surface nano-pattern for alignment and switching of LCs in device applications

Exposure and temperature dependences of contact angle of liquid crystals on photoaligning surface

Contact Info

Product

Resources

About