In semiconductor structuresSemiconductor structures with high-resistivity layers between oppositely directed potential barriers, under conditions of longitudinal illumination and barrier closure, a new functionality is revealed: the mutual compensation of photocurrents from the potential barriers and, consequently, the short-wave and long-wave spectral maxima. The long-wavelength maximum coincides with the intrinsic absorption band of the semiconductor. Certain technological solutions result in abnormally high photosensitivityHigh photosensitivity at spectral peaks. In some cases, this is expressed as a short-wavelength maximum, while in others, it appears as a long-wavelength maximum, which is the result of internal photocurrent amplification. Notably, the mutual compensation of oppositely directed photocurrents results in very small dark currents, on the order of 10 nA. This, in turn, provides a low signal-to-noiseSignal-to-noise ratio and enables the detection of weak light signals.