Analytical modeling of the CMOS-like a-Si:H TFT inverter circuit

The transfer characteristics of a CMOS-like hydrogenated amorphous silicon thin-film transistor (a-Si:H TFT) inverter circuit are analyzed. Accurate analytical expressions for the sheet conductance of the ambipolar a-Si:H TFT are simplified and applied to the CMOS-like TFT inverter circuit. The inverter circuit is composed of only one type of ambipolar a-Si:H TFT that is used for both the driver and load transistors. The CMOS-like inverter circuit has a very high small-signal gain compared to other types of TFT inverter circuits. An analytically calculated voltage transfer curve is almost identical to that obtained by the graphical method and shows very close agreement with the measured transfer curve.>