Fluorescent lights do use filaments. At each end of the tube there's a hot cathode - essentially a small incandescent filament designed to emit electrons rather

Fluorescent lights do use filaments. At each end of the tube there's a hot cathode - essentially a small incandescent filament designed to emit electrons rather than light. This is the source of the electrons that excite the gasses. While there are some designs that use cold cathodes these are not the common type as they are less efficient. Still won't make this filament treatment help though - sandwiching with layers would probably block the electrons.