Highly luminescent and free-standing, PVDF/doped ZnS nanocomposite films for flexible device applications

Zinc Sulphide doped with manganese (ZnS:Mn) and copper (ZnS:Cu) is well studied, due to its promising luminescence characteristics. Though there are numerous publications related to manganese and copper doped zinc sulphide, there are no reports on the growth of free standing and stable nanocomposite films of ZnS:Mn or ZnS:Cu with a polymer. The search for freestanding, flexible, mechanically and thermally stable films endowed with the excellent luminescent properties of doped zinc sulphide is the motivation behind the present studies. Poly(vinylidene flouride) (PVDF) is a fluoro polymer with impressive piezoelectric, ferroelectric and pyroelectric properties and at the same time highly flexible and processable. When PVDF/ doped ZnS nanocomposite film is placed in UV light, bright yellow orange luminescence is observed for the manganese doped film and blue luminescence, for the copper doped film. These nanocomposite films offer high prospects of wide range of applications in field emission displays, plasma displays and electroluminescent devices. By combining the yellow orange emission of ZnS:Mn and the blue emission of ZnS:Cu in the required optimised ratio, it is possible to develop white light emitting, freestanding, stable and flexible nanocomposite films of PVDF/doped ZnS.