Abstract: An a-Si FET comprising electrically conductive source and drain regions supported by an insulating substrate; a layer of amorphous silicon which is separately deposited in a space between said source and drain regions so as to engage the source and drain regions; source and drain electrodes electrically connected with said source and drain regions respectively; a gate electrode disposed adjacent said layer of amorphous silicon; and an insulating layer separating the gate electrode from the amorphous silicon layer; the arrangement being such that, in the ON state of the FET, a direct current-path is established in the layer of amorphous silicon which is disposed in said space. A low cost, low-temperature substrate such as soda glass may be used and the a-Si FET may be of the thin film type. Such an a-Si FET can be used in an LCD device which is addressed using one or more of the FET's.