A photon detection device includes a photodiode having a planar junction disposed in a first region of semiconductor material. A deep trench isolation (DTI) structure is disposed in the semiconductor material. The DTI structure isolates the first region of the semiconductor material on one side of the DTI structure from a second region of the semiconductor material on an other side of the DTI structure. The DTI structure includes a dielectric layer lining an inside surface of the DTI structure and doped semiconductor material disposed over the dielectric layer inside the DTI structure. The doped semiconductor material disposed inside the DTI structure is coupled to a bias voltage to isolate the photodiode in the first region of the semiconductor material from the second region of the semiconductor material.