Embodiments of forming an image sensor with an organic photodiode are provided. The organic photodiode uses dual electron-blocking layers formed next to the anode of the organic photodiode to reduce dark current. By using dual electron-blocking layers, the values of highest occupied molecular orbital (HOMO) for the neighboring anode layer and the organic electron-blocking layer are matched by one of the dual electron-blocking layers to form a photodiode with good performance. The values of the lowest occupied molecular orbital (LOMOs) of the dual electron-blocking layers are selected to be lower than the neighboring anode layer to reduce dark current.