A pixel for a CMOS photo sensor with increased full well capacity is disclosed. The pixel having a photosensitive element, a photo gate, potential well and a readout circuit. The photosensitive element having a front side and a back side, for releasing charge when light strikes the back side of the photosensitive element. The potential well receives the released charge from the photosensitive element. The photo gate located on the front side of the photosensitive element, for transferring the released charge from the potential well to a sense node. The readout circuit coupled to the sense node, for measuring a voltage corresponding to the released charge transferred to the sense node.