Active matrix pixel device with photo sensor

An active matrix pixel device including a plurality of polycrystalline silicon islands supported by a substrate, one of the polycrystalline silicon islands providing a channel and doped source/drain regions of a thin film transistor, a PIN diode which includes a p-type doped region, and an n-type doped region separated by an amorphous silicon intrinsic region. The amorphous silicon intrinsic region overlies and contacts at least a part of one of the polycrystalline silicon islands which provides one of the p-type or n-type doped regions of the PIN diode. The doped source/drain regions and said one of the p-type or n-type doped regions of the PIN diode are provided by the same polycrystalline silicon island and a vertical n-i-p stack is used by using a doped region of a polysilicon thin film transistor (TFT) for the n-type doped region.