P-117: The Investigation of Photo Alignment Polyimide Material for Large Size IPS Display

Ren, Wei; Hsieh, Chung‐Ching; Zhao, Yongchao; Zhao, Ren-Tang; Song, Yanxin; Li, Xiang; Yuan, Chun-Ge; Chiu, Chung‐Yi; Lee, Chia-Yu

doi:10.1002/sdtp.11005

Cited by 2 publications

(2 citation statements)

References 6 publications

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“…The NPs were well dispersed in the PI solution due to the organic alkyl chains of stearic acid. The prepared PI mixtures of each ratio were coated on the ITO substrates and then thermally cured at 200 °C for 1 h. Thus, the functional hybrid PI alignment layer with a thickness of approximately 100 nm was prepared [ 28 , 29 ].…”

Section: Methodsmentioning

confidence: 99%

Fabrication of TiO2-Embedded Polyimide Layer with High Transmittance and Improved Reliability for Liquid Crystal Displays

Son

Choi

et al. 2021

Polymers

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Construction of liquid crystal (LC) alignment by introducing polyimide (PI) to indium tin oxide (ITO) electrodes is one of the main methods to realize high-resolution images in liquid crystal displays (LCD). However, the loss of transmittance caused by the difference in refractive index between ITO and PI leads to direct degradation of LCD performance. Thus, we herein fabricated a functional hybrid PI alignment layer that reduces the difference in refractive index and greatly increases the transmittance of the device by introducing inorganic titanium dioxide (TiO2) nanoparticles (NP) to the organic PI. The highly refractive TiO2 NPs were surface-treated with stearic acid comprising long alkyl chains to improve their dispersibility and uniformly dispersed in the PI matrix by simply stirring the mixture. The hybrid PI mixture was spin-coated on the ITO substrate, and the resulting LC cell exhibited excellent electro-optical properties. In addition, the reliability of the LC cells was enhanced by the inclusion of the TiO2 NPs, which was confirmed through the evaluation of voltage holding ratio, residual direct current, and LC cell reliability. Overall, functional hybrid PI can be used in advanced display technology for next-generation LC devices that require high transmittance and reliability.

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Section: Methodsmentioning

confidence: 99%

Fabrication of TiO2-Embedded Polyimide Layer with High Transmittance and Improved Reliability for Liquid Crystal Displays

Son

Choi

et al. 2021

Polymers

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“…[15][16][17][18][19][20] The anisotropic inter-molecular interactions between alignment layer surfaces and the LC molecules have been observed to be strong enough to align the LCs on the alignment layer surfaces. 21 The photosensitive PI layers undergo various photochemistry reactions, such as photodecomposition, 22 photoisomerization, 23 or photocrosslinking 24 to realize the anisotropy in the PI molecular chains dependent on the polarization direction of LPUV sources. Thus, LC molecules can achieve uniform alignment on the PI layers although the anchoring energy might be lower than that of rubbing procedure.…”

mentioning

confidence: 99%

Preparation and characterization of photo‐decomposable ester‐containing semi‐alicyclic polyimide alignment layers for potential applications in in‐plane switching thin‐film transistor liquid crystal display devices

Zhi

Wang²,

Jia³

et al. 2022

Polymers for Advanced Techs

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Poly(amic acid)s (PAAs) alignment agents have been prepared from the alicyclic dianhydrides, including 1,2,3,4‐cyclobutanetetracarboxylic dianhydride (CBDA, I), 1,3‐dimethyl‐1,2,3,4‐cyclobutanetetracarboxylic dianhydride (DMCBDA, II), and ester‐linked aromatic diamines, including 4‐aminophenyl‐4′‐aminobenzoate (APAB, a) and bis(4‐aminophenyl)terephthalate (BPTP, b), respectively. The derived PAAs, including PAA‐Ia (CBDA‐APAB), PAA‐Ib (CBDA‐BPTP), and PAA‐IIa (DMCBDA‐APAB) exhibited the preferable molecular weights, while the PAA‐IIb (DMCBDA‐BPTP) showed the low one due to the low polymerization reactivity both for the DMCBDA dianhydride and the BPTP diamine. All the PAA solutions except PAA‐IIb were adopted as the alignment components to fabricate liquid crystal (LC) minicells with a mode of in‐plane switching (IPS). The polyimides (PI) alignment layers derived from the thermal dehydration reaction of the PAA precursors at 230°C for 30 min showed good alignments effects to the LC molecules, which exhibited the pretilt angles (θp) from 0.09 to 0.15° after being exposed by the linear polarized ultraviolet light sources with the wavelength of 254 nm. In addition, the PI alignment layers afforded good optoelectronic features to the minicells, including the voltage holding ratio values over 97% at room temperature, and the residual direct circuit voltages lower than 1.0 V. The anchoring energy results indicated that the PI‐IIa (DMCBDA‐APAB) alignment layer showed the highest interaction with the LC molecules, and thus exhibited the highest threshold voltage (Vth) in the voltage‐transmittance (V‐T) measurements for the minicells.

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P-117: The Investigation of Photo Alignment Polyimide Material for Large Size IPS Display

Cited by 2 publications

References 6 publications

Fabrication of TiO2-Embedded Polyimide Layer with High Transmittance and Improved Reliability for Liquid Crystal Displays

Fabrication of TiO2-Embedded Polyimide Layer with High Transmittance and Improved Reliability for Liquid Crystal Displays

Preparation and characterization of photo‐decomposable ester‐containing semi‐alicyclic polyimide alignment layers for potential applications in in‐plane switching thin‐film transistor liquid crystal display devices

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