A photodetector includes a semiconductor substrate having an irradiation zone configured to generate charge carriers having opposite charge carrier types in response to an irradiation of the semiconductor substrate. The photodetector further includes an inversion zone generator configured to operate in at least two operating states to generate different inversion zones within the substrate, wherein a first inversion zone generated in a first operating state differs from a second inversion zone generated in a second operating state, and wherein the first inversion zone and the second inversion zone have different extensions in the semiconductor substrate. A corresponding method for manufacturing a photodetector and a method for determining a spectral characteristic of an irradiation are also described.