Image sensor with improved optical response uniformity

An image sensor includes a semiconductor substrate; a photosensor having, a first photosensing region including a first stack of one or more layers of transparent materials covering the substrate, the first photosensing region having a spectral response having minima and maxima as a function of wavelength of light; a second photosensing region including a second stack of one or more layers of transparent materials covering the substrate, the second photosensing region having a spectral response having maxima and minima; and a third photosensing region including a third stack of one or more layers of transparent materials covering the substrate, the third photosensing region having a spectral response having maxima and minima; and wherein at least one maximum or minimum of the spectral response of the separate regions is matched with a minimum or maximum such that the average spectral response of the photosensor has less variation with wavelength of light than the individual spectral responses of each of the separate photosensing regions.