Guest-host active matrix liquid-crystal display using high-voltage polysilicon thin-film transistors

The construction and addressing of an experimental 30*30 actively addressed guest-host (G-H) liquid-crystal display (LCD) driven by polysilicon-based thin-film transistors (TFTs) is described. The design features are similar to those of high-quality, nonactive matrix addressed G-H displays used in avionics. The driving voltage is 23 V, resulting in a peak load of 46 V across the TFTs during polarity reversals. The triple-gated TFTs exhibited subnanoampere leakage currents at 40 V and mobilities, corrected for dopant diffusion under the gate, of 72 cm/sup 2//V-s for electrons and 40 cm/sup 2//V-s for holes. Because no polarizers are used, the display has a 180 degrees viewing angle and is highly readable in reflective-, transmissive-, and mixed-mode operations.>