Fabrication and optical properties of mesoporous ZnSe nanosheets@SiO₂ nanocomposites

Generally, the combination of semiconductor nanomaterials and an inert matrix could form a new material with enhanced optical property and corrosion resistance. Herein, 2D mesoporous sheet-like ZnSe nanostructure assembled from lots of 0D nanoparticles was first fabricated, the possible growth mechanism was proposed. Due to the presence of two different dimensions in ZnSe nanosheets (NSs), two absorption peaks around 421 and 480 nm were observed in the UV–Vis absorption spectrum. The violet, blue and green emissions were observed in the room-temperature PL spectrum of ZnSe NSs. Then, ZnSe NSs@SiO₂ nanocomposites were synthesized by a modified Stöber method. After coated with SiO₂, the LO phonon peak of ZnSe was asymmetrically broadened and weakened. When the adding amount of TEOS was 0.2 ml, the blue emission intensity of ZnSe NSs@SiO₂ was more than eleven times that of bare ZnSe NSs, the corrosion resistance was enhanced. Different emission peaks were observed in the violet-blue and visible region of ZnSe NSs@SiO₂. The optical properties of ZnSe NSs have been effectively regulated by adjusting the adding amount of TEOS, indicating the effective surface passivation by SiO₂.