The switching between on and off states of nematic liquid crystal pixels can be controlled with thewell-known electro-optic effect. This effect however presents a fast response at switching on theelectric field but a slow response at switching it off. Here we show a suitable choice of materials,cell geometries, surface preparations, and time dependence of the applied voltage that leads to aswitch off response as fast as that at switch on. This is due to the particular conductivity mechanismin polymers with aromatic rings leading to rectifying properties when deposited on top of indium tinoxide surface. A transient negative charge at polymer–liquid crystal interface favors a faster andstronger planar orientation of the nematic molecules diminishing drastically the switch off time andincreasing the contrast ratio. These facts, interesting enough from a fundamental point of view,could also lead to important technological consequences.
Fast electro-optic switching in nematic liquid crystals
SCARAMUZZA, Nicola
2004-01-01
Abstract
The switching between on and off states of nematic liquid crystal pixels can be controlled with thewell-known electro-optic effect. This effect however presents a fast response at switching on theelectric field but a slow response at switching it off. Here we show a suitable choice of materials,cell geometries, surface preparations, and time dependence of the applied voltage that leads to aswitch off response as fast as that at switch on. This is due to the particular conductivity mechanismin polymers with aromatic rings leading to rectifying properties when deposited on top of indium tinoxide surface. A transient negative charge at polymer–liquid crystal interface favors a faster andstronger planar orientation of the nematic molecules diminishing drastically the switch off time andincreasing the contrast ratio. These facts, interesting enough from a fundamental point of view,could also lead to important technological consequences.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.