Various embodiments of the present application are directed towards a semiconductor-on-insulator (SOI) DoP image sensor and a method for forming the SOI DoP image sensor. In some embodiments, a semiconductor substrate comprises a floating node and a collector region. A photodetector is in the semiconductor substrate and is defined in part by a collector region. A transfer transistor is over the semiconductor substrate. The collector region and the floating node respectively define source/drain regions of the transfer transistor. A semiconductor mesa is over and spaced from the semiconductor substrate. A readout transistor is on and partially defined by the semiconductor mesa. The semiconductor mesa is between the readout transistor and the semiconductor substrate. A via extends from the floating node to a gate electrode of the readout transistor.