Influence of charge transfer complex doping of polyamide alignment film on SSFLC cell performance

New alignment films for surface stabilized ferroelectric liquid crystals displays (SSFLCD's) have been produced by doping standard polyamide alignment films with an organic conducting charge transfer complex. The doping process exploits absorption equilibrium between a solution of the dopant and the polymeric solid phase. Dopant concentration in the solid state has been evaluated by spectrophotometric analysis in the UV-visible range. Test displays with ITO electrodes and doped alignment layers have been fabricated and their performance evaluated with new techniques. It has been found that optical response is a function of dopant concentration in the alignment layer and that display performances can improve at an optimum concentration. In fact addressing hysteresis is reduced at low dopant concentration but increases at higher concentrations.