Back-bias effect on the current-voltage characteristics of amorphous silicon thin-film transistors

Abstract The electrical potential of the back-surface of amorphous silicon thin-film transistors is controlled by a back bias, V bb , applied to the back-gate electrode of a dual-gate structure. The threshold voltage of the transistor moves in the negative direction when V bb is positive; this movement is similar to the substrate-bias effect of conventional metal-oxide-semiconductor transistors. The type of majority carriers of the off-current is determined by the polarity of the V bb : electrons for V bb > 0 V and holes for V bb