Spd films and light valves incorporating overcoatings which enhance film adhesion to substrates, have good cohesion and protect against electrical short circuits

A method of making an electro-optical device for controlling the transmission of radiation, said device comprising a cell formed of opposed cell walls, a light-modulating element between the cell walls and opposed electrode means operatively associated with the cell walls, said light modulating element comprising a film formed of a matrix polymer material having droplets of liquid light valve suspension comprising a plurality of particles dispersed in a liquid suspending medium distributed within the matrix, wherein said method comprises

• providing at least one layer of an overcoating on at least a portion of a surface between the electrode means and the light modulating element, said overcoating formed from a material comprising a member selected from the group consisting of (a) titanium dioxide (TiO2) alone and (b) a combination of SiOx and an inorganic material having an index of refraction at 589 nm greater than 1.54.