A method for manufacturing a multi-spectral photodiode array in a CdxHg1-xTe semiconductor layer constituted of pixels, the method including a step of producing a PN junction in each pixel and further includes producing a cadmium-rich structure on the semiconductor layer, structured so that all the pixels are not surmounted by a same quantity of cadmium atoms, this quantity being able to be zero; and inter-diffusion annealing, realizing the diffusion of cadmium atoms from the cadmium-rich structure to the semiconductor layer. Pixels that do not all have the same cutoff wavelength are thereby obtained.