Grain Boundaries Obsevation of Polycrystalline Sillcon Using Nematic Liquid Crystals with Positive Dielectric Anisotropy

Abstract

A new method to analyze electrically active grain boundaries of polycrystalline silicon by using a field effect of nematic liquid crystal with positive dielectric anisotropy is described. In addition, threshold voltage of a liquid crystal planar cell with interdigited comb metal electrdes is measured as a function of frequency and temperature. From the results, the fringing electric field effect on the liquid crystal molecular orientation is clarified. This method is advantageous in the wide frequency range (0.1–10⁵ Hz), fast response time and low threshild voltage by comparison with the method using nematic liquid crystal with negative dielectric anisotropy.