Laminated glazing with coloured reflection and high solar transmittance suitable for solar energy systems

Laminated and etched glazing unit for architectural integration of solar energy systems comprising a substrate delimited by two main faces and a multi-layered interference filter also delimited by two main faces, one main face of said substrate being adapted to be in contact with an incident medium, the other main face being in contact with a main face of said interference filter, the other main face of said interference filter being adapted to be in contact with an exit medium; said incident medium having a refractive index ninc = 1, said substrate having a refractive index nsubstrate defined as follows : 1.45≤ nsubstrate ≤ 1.6 at 550 nm, and said exit medium being defined as follows 1.45≤ nexit ≤ 1.6 at 550 nm; and wherein said unit is designed in such a way that the following requirements are met : 1a) The saturation of the colour, given by Cab = √ (a)2 + (b*)2, according to the CIE colour coordinates L*, a* and b* under daylight illumination CIE-D65 is higher than 8 at near-normal angle of reflection, except for grey and brown. 1b) The visible reflectance at near-normal angle of reflection Rvis is higher than 4%. 1c) The variation of the dominant wavelength λMD of the dominant colour MD of the reflection with varying angle of reflection Θr is smaller than 15 nm for Θr < 60°. 1d) The total hemispherical solar transmittance at near-normal incidence is above 80%.