Tuning Ag⁺ and Mn²⁺ doping in ZnS:Ag,Mn embedded polymers for flexible white light emitting films

Abstract

Flexible Light Emitting Diodes are versatile lighting solutions that offer bendable and adaptable illumination possibilities. A soft, flexible white luminescent film (1 mm) shows promise for foldable electroluminescent devices and applications. This film was fabricated using ZnS:Ag and Mn. Under different excitation wavelengths, the phosphors emit blue light due to Ag+ luminescence centers and red light from the d-d transition of Mn2+. The blue emission is greatly suppressed at high Mn2+ doping levels, requiring reduced Ag+ doping in co-doped ZnS:Ag,Mn compared to solo-doped ZnS:Ag samples. By adjusting Ag+ and Mn2+ concentrations, the ZnS:Ag(1%),Mn(0.2%) phosphors show a proper intensity ratio of blue and red emissions, making them a promising candidate for future white light applications.