Embodiments relate to photoreceivers, such as photodiodes. In one embodiment, an integrated circuit device comprises a photodiode, and an electrode arranged over or on top of the photodiode. The electrode is substantially transparent or otherwise exhibits a lower absorption rate, such that light or other radiation can pass through the electrode to the photodiode. Varying a charge applied to the electrode enables the spectral sensitivity of the underlying photodiode to be altered, tuned or otherwise adjusted.