Photodiode, comprising: ∘ a detection portion, having a first surface and a second surface opposite each other and parallel to a main plane, made of a first germanium-based crystalline semiconductor material, comprising: • a first n-type doped region, and flush with the first surface; • a second p-type doped region, and flush with the second surface; • an intermediate region, located between the first region and the second region and surrounding the first region in the main plane; o a peripheral semiconductor portion, made of a second p-type doped semiconductor material, surrounding the detection portion in the main plane and coming into contact with the second region; o an interposed semiconductor portion, disposed on and in contact with the first region of the detection portion; o metal contacts (32.1, 32.2), disposed on the side of the first surface, and adapted to electrically bias, on the one hand, the first region by means of the interposed semiconductor portion and, on the other hand, the second region by means of the peripheral semiconductor portion; o characterized in that the interposed semiconductor portion is made of a third crystalline semiconductor material having: • a natural lattice parameter equal, to within 1%, to a natural lattice parameter of the first germanium-based semiconductor material; • a bandgap energy at least 0.5 eV higher than that of the first germanium-based semiconductor material. ∘ a detection portion, having a first surface and a second surface opposite each other and parallel to a main plane, made of a first germanium-based crystalline semiconductor material, comprising: • a first n-type doped region, and flush with the first surface; • a second p-type doped region, and flush with the second surface; • an intermediate region, located between the first region and the second region and surrounding the first region in the main plane; • a first n-type doped region, and flush with the first surface; • a second p-type doped region, and flush with the second surface; • an intermediate region, located between the first region and the second region and surrounding the first region in the main plane; o a peripheral semiconductor portion, made of a second p-type doped semiconductor material, surrounding the detection portion in the main plane and coming into contact with the second region; o an interposed semiconductor portion, disposed on and in contact with the first region of the detection portion; o metal contacts (32.1, 32.2), disposed on the side of the first surface, and adapted to electrically bias, on the one hand, the first region by means of the interposed semiconductor portion and, on the other hand, the second region by means of the peripheral semiconductor portion; o characterized in that the interposed semiconductor portion is made of a third crystalline semiconductor material having: • a natural lattice parameter equal, to within 1%, to a natural lattice parameter of the first germanium-based semiconductor material; • a bandgap energy at least 0.5 eV higher than that of the first germanium-based semiconductor material. • a natural lattice parameter equal, to within 1%, to a natural lattice parameter of the first germanium-based semiconductor material; • a bandgap energy at least 0.5 eV higher than that of the first germanium-based semiconductor material.