Ion-beam-spurted dimethyl-sulfate-doped PEDOT:PSS composite-layer-aligning liquid crystal with low residual direct-current voltage

Abstract

Thin ion-beam (IB)-spurted dimethyl sulfate/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (DMS/PEDOT:PSS) layers with improved electro-optic performance are presented for aligning liquid crystals. IB spurting is effective for enhancing the conductivity of such layers, as well as the anchoring energy of the liquid crystals sandwiched between them. Compared with a commercial twisted-nematic cell assembled with polyimide alignment layers, the same cell assembled with 3.0-keV IB-spurted DMS/PEDOT:PSS alignment layers shows a 38% faster switching and a 93% lower residual direct current. The improved electro-optic performance here is likely due to the enhanced electric field effect and the charge-releasing ability of thin IB-spurted DMS/PEDOT:PSS layers.

Vanadium Dioxide Nanoparticle Doped Polyimide Hybrid Alignment Layers for Flexible Liquid Crystal Displays

“…Alignment of LCs was characterized using polarized optical microscopy (POM, BXP 51, Olympus, Japan), and the tilt angles of LCs were evaluated by means of a crystal rotation method (TBA 107, Autronic, Germany), in which the fluctuating transmittance was recorded with each antiparallel cell being rotated latitudinally from −70 to +70°. The anchoring energy of LCs on hybrid alignment layers was characterized by the capacitance–voltage ( C – V ) hysteresis method (LCR meter, 4284A, Agilent, USA) with a step bias voltage of 0.1 V and a maximum bias voltage of 10 V . The operating voltage and the response time of cells were evaluated using an automatic LC testing system (ALCT-EO1S, Instec, USA) with a step bias voltage of 0.2 V and a maximum bias voltage of 5 V, and the bendability of flexible cells was evaluated by observing the alignment of LCs in bent cells under various radii.…”

The Effect of Operating Temperature on the Response Time of Optically Driven Liquid Crystal Displays

“…The processing procedure presented in Figure 1C enables us to control the precise micro-domain alignment of the LC by simply modulating the easy axis of the exposing light. As the SD1 molecules follow the perpendicular polarization direction of the incident light, distinct tunable patterns with different alignment orientations can be realized by a two-step irradiation process [21][22][23]. The main operating principle of the ODLCD is switching between planar and twist nematic electro-optical modes [19].…”

“…different alignment orientations can be realized by a two-step irradiation process [21][22][23].The main operating principle of the ODLCD is switching between planar and twist nematic electro-optical modes [19].…”

Decreasing the Residual DC Voltage by Neutralizing the Charged Mobile Ions in Liquid Crystals

“…The moving of mobile ions driven by electric forces towards alignment layers results in their accumulation on alignment layers, which finally generates residual direct current (DC) voltage (V rdc ) inside LC cells and adversely affects LC' switching [1][2][3][4][5][6]. During the last several decades, a series of researches focused on distinguishing, detecting mobiles ions, and revealing the influences of mobile ions shifting on LC switching were conducted, and nowadays a lot of explorations are carried out to reduce mobile ions' adverse functions on LC [7][8][9][10][11][12] A lot of attempts have been adopted to prevent the influences of mobile ions on LC electro-optical performances, such as designing special LC molecules, purifying LC, doping LC [13,14], replacing the polyimide (PI) alignment layers with conductive materials [15][16][17][18], and photo-aligning LC [19][20][21], etc. Compared with other methods, doping is much easier; however, doping LC with nano-materials brings new issues, for instance, the doped nano-materials are too poor to be dispersed, and the aggregation of these nano-materials makes LC insensitively respond to external voltage.…”