Effects of carbon-nanotube doping on the performance of a TN-LCD

The electro-optical characteristics of a 90 twisted-nematic liquid-crystal display (TN-LCD) were analyzed. The test cell was composed of a minute amount of dopant, multiwalled carbon nanotubes, and a standard nematic mixture, E7, used in TN-LCDs with direct addressing. Under the experimental conditions, no hystereses in optical transmittance were observed in either the doped cell or a neat counterpart under an applied ac voltage. Experimental results show that doping with nanotubes rectifies the electro-optical properties of the cells by reducing the driving voltage as well as the rise time. Similar results were found in a TN cell of a TFT-grade liquid crystal instead of the mixture consisting completely of polar compounds.