Optical laminate comprising thermochromic layer having excellent optical properties due to control of photonic evaporation and photonic sintering conditions, and manufacturing method therefor

A method of preparing an optical laminate comprising a substrate and a thermochromic layer formed on the substrate, wherein the thermochromic layer includes a vanadium oxide cluster, the method comprising:

• a formation step of applying a solution containing vanadium oxide particles onto the substrate to form a coating layer;
• a photo-evaporation step of emitting light to remove organic matter from the coating layer;
• and
• a photo-sintering step of emitting light to photo-sinter the vanadium oxide particles contained in the coating layer to prepare a thermochromic layer including a vanadium oxide cluster;
• wherein the vanadium oxide cluster has a size of 20 to 250 nm;
• the optical laminate has maximum transmittance of 50% or more in a range of 400 to 800 nm;
• the thermochromic layer satisfies Equation 1 below:
• 1≤S (%)≤20 [Equation 1]
• where S is a pore area proportion measured by analyzing a picture obtained by a picture analysis apparatus capturing an upper surface of a sample, and
• wherein the thermochromic layer has a thickness of 0.1 to 5 μm.