Pouya Nosratkhah Heat and keep the substrate above the boiling point of your solvent - for example on a heating plate. Spray the liquid evenly across the substrate and flash evaporation of the solvent may leave you with a thin film. Alternatively, a low temperature vacuum evaporation to prevent decomposition.

For achieving an even thin film coating of SD1 on a hemispherical substrate, the two best methods are spray coating and electrospray deposition.

Spray coating allows uniform deposition by generating fine aerosol droplets that quickly evaporate, leaving a homogeneous layer on the surface. The gravitational effect is minimized, especially if the substrate is rotated during deposition. Key parameters such as pressure, spray rate, and substrate temperature must be carefully controlled to prevent uneven coverage.

Electrospray deposition works similarly but uses an electric field to create charged microdroplets that uniformly settle on the substrate. This method provides greater control over coating uniformity, especially for low-concentration solutions. If the substrate is conductive or grounded, deposition efficiency improves further.

Both techniques are well-suited for coating complex geometries, but if precise thickness control and uniformity are critical at low concentrations, electrospray deposition is the better option.