A transparent substrate provided with a functional stack of thin layers on at least one of its faces, the functional stack including, starting from the substrate, at least one metallic functional layer placed between two dielectric modules of thin layers, and wherein at least one of the dielectric modules of thin layers includes a layer of tungsten oxide, and the tungsten oxide includes at least one doping element selected from the chemical elements of group 1 according to the IUPAC nomenclature.

A transparent substrate provided on one of its main surfaces with a stack of thin layers, the stack of layers including the following layers starting from the substrate a first dielectric module of one or more thin layers; an absorbent layer of tungsten oxide; a second dielectric module of one or more thin layers; wherein the tungsten oxide includes at least one doping element selected from the chemical elements of group 1 according to the IUPAC nomenclature, the absorbent layer of tungsten oxide includes cesium as a doping element, and the molar ratio of cesium to tungsten is between 0.01 and 1.