Amorphous silicon p-i-n-i-p and n-i-p-i-n diodes

This letter describes the preparation and electrical characteristics of a-Si:H p-i-n-i-p and n-i-p-i-n thin-film diodes suitable for driving monochrome liquid crystal displays with more than 500 lines. The symmetrical current-voltage curves in the reverse breakdown regime can be described by i=i0 exp(E/E0), where E0≂9×104 V/cm. In the range 20–125 °C, the current is thermally activated with an energy of 0.25 eV. The response time to applied voltage pulses is ≤10 μs. The stability of the electrical characteristics is adequate for at least 104 h of operation in a liquid crystal display. Electrical characteristics indicate that the reverse breakdown current is a tunneling current injected into the i layer and that electrons are likely to be dominant.