Radiative cooling substrate and manufacturing method of the same

A manufacturing method of a radiative cooling substrate, comprising:

• forming a metallic substrate by depositing an adhesive layer with a second thickness on a silicon substrate and depositing a metal layer on the adhesive layer in an evaporation process, wherein the adhesive layer comprises chromium or titanium, and the second thickness is 10 nm to 50 nm;
• preparing a chitosan solution, the chitosan solution comprising chitosan and a solvent, wherein the solvent comprises water, C1-C4 alcohols, and an acid, and a pH-value of the chitosan solution is less than seven;
• providing the metallic substrate into an electrophoresis cell loaded with the chitosan solution;
• applying a voltage to the metallic substrate for a predetermined time period;
• depositing a chitosan layer comprising the chitosan with a first thickness on the metallic substrate in an electrophoretic process;
• and
• obtaining the radiative cooling substrate;
• wherein the first thickness is a value from 0.5 μm to 10 μm.