A method for alignment of a homeotropic liquid crystal cell by doping a percentage of a positive, neutral, or negative liquid crystal material, a high contrast ratio homeotropic alignment of difluoro compounds or mixtures is achieved, independent of operating temperature. Without special requirement on alignment layers, rubbing methods or pretilt angles, the uniform aligned homeotropic liquid crystal cell results even at high temperature and the physical properties, such as the birefringence and viscosity, of the liquid crystal mixtures are improved. In an embodiment the method the homeotropic vertically aligned nematic liquid crystal cells are used in the production of high contrast microdisplays. |