Preparation And Luminescent Properties Of Zns Luminescent Materials

ZnS luminescence nano-materials are prepared by hydrothermal synthesis and solid-statemethod at low temperature, characterized the phase, morphology and structure of the particleswith some method, such as XRD,TEM,SEM,UV-Vis,PL and so on and compared with thatof products of which were prepared by high temperature solid-state and precipitation methodin this paper.The particles obtained by hydrothermal synthesis are well crystallized and has narrowsize distribution, little agglomeration and homogeneity phase. With the increase concentrationof the surfactant, the particles become smaller and smaller. The excitation wavelength shows ablue shift and split to two excitation bands, while the emission wavelength shows a red shiftwith so prepared materials.A solid-state method for preparation of ZnS:Mn²⁺ and ZnS:Cu²⁺ nanoparticles are used inthis paper. The activated centers in ZnS matri (Mn²⁺ and Cu²⁺) have been doped successfullyand these excitation and emission spectra are different with the bulk materials, which can beattributed to quantum size effect. Comparing with high temperature solid state method, lowtemperature method has many virtues such as high yield, simple operation and environmentalfriendly. The emission bands of luminescence materials so prepared with a solid state methodat low temperature centered at 600nm, while the excitation band are at 347nm. The emission ofZnS:Mn can be attributed to a ⁴T₁ â†'6A₁ transition of Mn²⁺ ion. Cu²⁺ ions are assumed tosubstitute for Zn²⁺ or to be interstitial ions in Cu-doped nano crystallizes. For Cu-doped ZnSnano-crystallizes, the green luminescence centers of Cu²⁺ in their model is due to a transitionfrom the conduction band of ZnS to the 't2'level of excited Cu²⁺(d⁹) in the ZnS band gap. Theemission at 527nm attributed to the former and that at 485 attributed to the later.The PL properties of the luminescence particles changed with the production conditions,such as rubbing time, drying temperature and washing ways.