Patent ID: 8860029

Claim:
A photoelectric conversion element comprising: a first gate electrode; a first gate insulating layer over the first gate electrode; a crystalline semiconductor layer provided over the first gate insulating layer; amorphous semiconductor layers provided apart from each other, each of the amorphous semiconductor layers being on and in contact with the crystalline semiconductor layer: impurity semiconductor layers provided over the amorphous semiconductor layers, respectively; a source electrode and a drain electrode, each provided in contact with one of the impurity semiconductor layers; a second gate insulating layer provided to cover a portion of the crystalline semiconductor layer, where the amorphous semiconductor layers are not provided; and a second gate electrode provided over the second gate insulating layer, wherein a light-receiving portion is provided in the portion of the crystalline semiconductor layer, where the amorphous semiconductor layers are not provided, wherein the first gate electrode includes a light-shielding material and is provided to entirely overlap with the crystalline semiconductor layer and the amorphous semiconductor layers, wherein the second gate electrode includes a light-transmitting material and is provided to overlap with the light-receiving portion, and wherein the first gate electrode is electrically connected to one of the source electrode and the drain electrode.