The Study About Fabrication And Optical Properties Of Eco-friendly Doping ZnS Quantum Dots

Recently,the study of semiconductor quantum dots has became a hot topic due to their advantages including wide excitation spectra,good chemical stability and low toxicity and widespread application.In this paper,we used precipitation synthesis based on ZnS and fabricated the composite quantum dots by doping Ce³⁺?In³⁺and Mn²⁺with single,double and ternary doping.We also studied their mechanisms of formation,microstructures and light properties.1.Ce³⁺,In³⁺and Mn²⁺were doped into ZnS quantum dots for obtaining ZnS:Ce³⁺,ZnS:In³⁺,ZnS:Mn²⁺quantum dots.The results show that the structure of ZnS quantum dots are sphere with agglomeration and their particle sizes are about 6 10 nm.The luminescent properties of ZnS:Ce³⁺quantum dots are the best with an emission wavelength of 469 nm,and their fluorescence peak half maximum width?FWHM?is 39 nm.The ZnS:In³⁺quantum dots show an emission wavelength of 551 nm with FWHM at 20 nm.The ZnS:Mn²⁺quantum dots show an emission wavelength of 600 nm with a FWHM of 55 nm.We found that the fluorescence intensity increases at first and then decreases when the time of ZnS:Ce³⁺quantum dots in aqueous solution increases and their fluorescence spectral peaks showed the obvious blue shift.2.Ce³⁺,In³⁺and Mn²⁺were double doped into ZnS quantum dots for obtaining ZnS:Ce³⁺/In³⁺,ZnS:Mn²⁺/Ce³⁺,ZnS:Mn²⁺/In³⁺quantum dots.The results show that the ZnS:Ce³⁺/In³⁺quantum dots show an emission wavelength of 468 nm with FWHM at 38 nm.The ZnS:Mn²⁺/Ce³⁺quantum dots show an emission wavelength of 580 nm with a FWHM of 63nm.With the content of Ce³⁺increased,the emission peak of ZnS:Mn²⁺/Ce³⁺appeared red shift.The ZnS:Mn²⁺/In³⁺quantum dots show an emission wavelength of 580 nm,with FWHM at 56nm.3.Ce³⁺,In³⁺and Mn²⁺were ternary doped into ZnS quantum dots for obtaining ZnS:nCe³⁺/0.5In³⁺/1.0Mn²⁺,ZnS:1.5Ce³⁺/nIn³⁺/1.0Mn²⁺,ZnS:1.5Ce³⁺/1.0In³⁺/nMn²⁺quantum dots.The results show that there are three emission peaks whose wavelengths are 387 nm,450nm and 584 nm with FWHM at 11 nm,85 nm and 64 nm in the ZnS:nCe³⁺/0.5In³⁺/1.0Mn²⁺quantum dots.The light intensity enhanced with the increase of Ce³⁺amount.The wavelength of ZnS:1.5Ce³⁺/n In³⁺/1.0Mn²⁺is 379 nm,438 nm and 580 nm.The FWHM are 11 nm,142nm and65nm.The light intensity enhanced with the increase of In³⁺amount.The wavelength of ZnS:1.5Ce³⁺/1.0In³⁺/nMn²⁺is 383nm,440nm and 581nm.The FWHM are 9 nm,88nm and 69nm.ZnS:1.5Ce³⁺/1.0In³⁺/nMn²⁺is getting bright strongly in 583nm with the increase of its number.When the content is 0.1%,ZnS:1.5Ce³⁺/1.0In³⁺/nMn²⁺comes to the maximum.However,it begins to decrease when the content of mixture is 4.5 times of 0.1%.