Thin Film Transistor-Addressed Display Device.

The objective of this program is a 6 x 6 inch, 20 lpi, thin-film transistor matrix addressed ac-EL display. A major step forward was achieved in this reporting period. The thin film transistors were optimized and show more than adequate ONOFF current ratios. The transistors were able to switch 200V. Many complete matrices were made showing acceptable properties. A phosphor screening and display package process was developed and complete 6 x 6 inch 20 lpi displays fabricated. The partial operation of several displays was demonstrated with alphanumeric data being readily discernible. Extensive life and stability tests on the thin film transistors were conducted. Our 100,000 device hours of high voltage operation was obtained without a single failure. There was a small drift in drain current but this was reversible and would not affect display operation with many years of use.