用静态和动态辐射等离子流处理基板上的液晶取向  

Liquid Crystal Alignment on Substrates Treated with the Plasma Flux:Static and Dynamic Regimes of Irradiation

作　　者：Oleg Yaroshchuk Ruslan Kravchuk Andriy Dobrovolskyy C.-D.Lee P.-C.Liu Liou Qiu Oleg D.Lavrentovich 马红梅[4] 

机构地区：[1]NASU物理研究所 [2]台湾工业技术研究所 [3]肯特大学液晶研究所化学Chemica lInterdisplinary Program [4]河北工业大学应用物理系

出　　处：《现代显示》2004年第6期27-31,20,共6页Advanced Display

摘　　要：在本文,我们介绍关于液晶取向的新成果,基板用阳极分层推进器(anodelayersthruster,ALT)产生的加速氩等离子体“层(sheet)”作倾斜处理。由有机的(聚合物)和无机的(玻璃,类金刚石(DLC),二氧化硅等)原材料做成的基板,用等离子体流在静态和动态(垂直于等离子体层方向单向变化)方式下进行处理。对于正性液晶(△ε>0),在两种方式下观察到两种取向模式:易取向轴限制在入射等离子层平面内(模式1)或垂直于这个平面(模式2)。在第1种取向模式中,液晶的预倾角不等于零,并且随着等离子体束入射角和辐射量而变化,其均匀性在动态辐射中更好。随着辐射的增强,会发生模式1到模式2的转变。应用于垂面取向液晶显示器(VALCD)的负性液晶混合物(△ε<0),只有第1种模式(在整个基板上一致取向)被观察到,在辐射量低或高(正性液晶出现第2种取向模式时的相对高的辐射量)时都能出现。预倾角可高达30°,由等离子束的辐射量和入射角来控制。第2种模式在高辐射下出现,并且只在静态方式下,位于等离子层中心的、比较密集的区域,而第1种取向模式在其外围。模式1和模式2由狭窄的过渡区分开,该区呈现多畴液晶取向(二重简并)。这些畴的易取向轴相对于模式1中取向方向大约偏转±45°。对于负性液晶,由模式1到二重简并到模式2转变的取向方式,?In this paper, we present the new results related to LC alignment on the substrates obliquely treated with a 'sheet' of accelerated Ar+ plasma generated by an anode layers thruster(ALT). The substrates of organic (polymers) and inorganic (glass, DLC, SiO2 etc.) origin were treated with the plasma flux in static and dynamic regime (unidirectional translation perpendicularly to plasma 'sheet'). For LCs with△ , in both regimes, we observed two aligning modes, with the easy axisconfined to the plane of plasma incidence (mode 1) or perpendicular to this plane (mode 2). In the 1st aligning mode the LC pretilt angle is not equal to zero and can be varied with the incidence angle of plasma beam and the irradiation dose. The uniformity of pretilt angle is better in the dynamic regime. With the increase of irradiation dose, the alignment transition from the 1st to the 2nd mode occurs. For the LC mixtures with△ for VA LCD, only the 1st mode alignment (uniform over the whole substrate) is realized. It occurs at low and even at the relatively high irradiation doses,which cause the 2nd mode alignment for the LCs with△ The pretilt angle achieves values as high as 300 and can be controlled by the irradiation dose and by the incidence angle of plasma beam. The 2nd alignment mode is observed at high irradiation doses and only in the static regime of irradiation. It occurs in the central, most intensive part, of the plasma 'sheet', while the periphery part shows the 1st mode. The areas of the 1st and the 2nd mode are sep arated with the narrow transition area showing multidomain (two-fold degenerate) LC alignment. The easy axis in thesedomains is turned by about 皐ith respect to the alignment direction in the 1st mode area. The alignment transition 1st mode-two-fold degenerate alignment-2nd mode observed for LC with△ is quite similar to the one earlier described for vapor deposition alignment. In the dynamic irradiation regime, for both types of LC, uniform alignment on the substrates as big as 15x15 cm2 is realized.

关 键 词：液晶 粒子束处理 液晶取向 

分 类 号：TN141.9[电子电信—物理电子学]