No, UV is unrelated to your issue.

First you need to figure out if it’s a surface infestation because of condensation or if it’s a constructive thermal bridge. The latter can be solved by raising the surface (wall, ceiling, etc) temperature through insulation or more inefficiently special heaters designed for this purpose.

In both cases, the contaminated material is removed down to the plaster or masonry. Wood, wallpaper and similar materials will likely be deeply contaminated and must be removed. For areas larger than 1 sq meter, it’s better to get a specialized contractor which will use HEPA vacuum cleaners, special bags, etc to ensure that the mould spores don’t spread in other rooms.

For small areas the agents of choice are bleach or hydrogen peroxide, both available in products for home use.