The photodetector includes a photon absorbing region formed by a first semiconductor material having a first bandgap energy value. It also includes a blocking region formed by at least second and third semiconductor materials configured to prevent the majority charge carriers from passing between the photon absorbing region and a contact region, the second semiconductor material presenting a second bandgap energy value higher than the first bandgap energy value to form a quantum well with the third semiconductor material. The blocking region is doped.