Luminescent silica films prepared using perhydropolysilazane and Mn-doped ZnS nanophosphors

Luminescent films have many applications in industry such as display, lightings, and solar cells. To fabricate such films, composites of luminescent materials and organic resins are often considered. However, organic resins have a drawback of low long-term stability, especially under continuous exposure to UV light. In this manuscript, we investigate synthesis of ZnS:Mn²⁺ nanocrystals for highly luminescent materials composed of earth abundant elements, and fabrication of a luminescent silica film emibedding the ZnS:Mn²⁺ nanocrystals. We synthesized the ZnS:Mn²⁺ nanocrystals by a precipitation method and optimized their luminescent properties by Mn-doping concentrations. Perhydropolysilazane was chosen for a silica precursor since it allows easy fabrication of silica thin films by solution printing methods. Luminescent thin films were obtained by doctor-blade method using a colloidal solution of ZnS:Mn²⁺ nanoparticles dispersed in perhydropolysilazane solution. Curing of the printed layer was optimized and complete transformation to silica was realized without compensating luminescent properties of embedded ZnS:Mn²⁺ nanocrystals.