Photovoltaic module comprising at least one photovoltaic cell and at least one concentration optic device (Oc), intended to be illuminated by a light flux emitting at a plurality of illumination wavelengths (λ i) belonging to a band of wavelengths defined by a minimum wavelength (λ min) and a maximum wavelength (λ max), said band of wavelengths being that of the solar radiation of the order of [380 nm-1600 nm], characterised in that: - said concentration optic device is a monolithic component comprising: • on one surface, a diffractive structure comprising subwavelength patterns, defined in a so-called structured material, ensuring a diffraction function, said patterns having at least one dimension less than or equal to the average illumination wavelength λ c situated between λ min and λ max divided by the refractive index of said structured material and said patterns being separated from one another by subwavelength distances, defined between centres of adjacent patterns • on the other surface, a focusing structure comprising a refractive optic or a diffractive structure with subwavelength patterns, defined in a so-called structured material, or - said concentration optic device is a monolithic component comprising a diffractive structure with subwavelength patterns defined in a so-called structured material ensuring on a same surface a focusing function and a diffraction function, said patterns having at least one dimension less than or equal to the average illumination wavelength λ c situated between λ min and λ max divided by the refractive index of said structured material and said patterns being separated from one another by subwavelength distances, defined between centres of adjacent patterns. - said concentration optic device is a monolithic component comprising: • on one surface, a diffractive structure comprising subwavelength patterns, defined in a so-called structured material, ensuring a diffraction function, said patterns having at least one dimension less than or equal to the average illumination wavelength λ c situated between λ min and λ max divided by the refractive index of said structured material and said patterns being separated from one another by subwavelength distances, defined between centres of adjacent patterns • on the other surface, a focusing structure comprising a refractive optic or a diffractive structure with subwavelength patterns, defined in a so-called structured material, or • on one surface, a diffractive structure comprising subwavelength patterns, defined in a so-called structured material, ensuring a diffraction function, said patterns having at least one dimension less than or equal to the average illumination wavelength λ c situated between λ min and λ max divided by the refractive index of said structured material and said patterns being separated from one another by subwavelength distances, defined between centres of adjacent patterns • on the other surface, a focusing structure comprising a refractive optic or a diffractive structure with subwavelength patterns, defined in a so-called structured material, or - said concentration optic device is a monolithic component comprising a diffractive structure with subwavelength patterns defined in a so-called structured material ensuring on a same surface a focusing function and a diffraction function, said patterns having at least one dimension less than or equal to the average illumination wavelength λ c situated between λ min and λ max divided by the refractive index of said structured material and said patterns being separated from one another by subwavelength distances, defined between centres of adjacent patterns.