Low-voltage cathodoluminescence properties of green-emitting ZnAl2O4:Mn2+ nanophosphors for field emission display

A low-cost ZnAl2O4:Mn2+ green nanophosphor for field emission display (FED) was successfully synthesized by the coprecipitation method and a two-step firing, firstly calcining at 1200 °C for 2 h in air and then annealing at 900 °C for 3 h in flowing NH3 gas. The effects of the preparation process and the Mn2+ concentration on optical properties of ZnAl2O4:Mn2+ were investigated. The phase composition, particle morphology, photoluminescence (PL) spectra of the ZnAl2O4:Mn2+ phosphor as well as low-voltage field emission properties of the FED device prepared by using the synthesized ZnAl2O4:Mn2+ phosphor were examined. Similar to ZnGa2O4:Mn2+, Mn2+-doped ZnAl2O4 showed two green emission bands centered at 508 and 517 nm, respectively, which originate from 4T1(4G)→6A1(6S) transitions of Mn2+ on Td and Oh sites. The PL intensity reached the maximum at 0.5 at.% Mn2+. Under the low-voltage excitation, the FED device exhibited bright green emission, high voltage brightness saturation, and high color purity.

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► ZnAl2O4:Mn2+ nanophosphor for FED was successfully synthesized by coprecipitation.
► The powders were firstly fired at 1200̊C in air and then reduced at 900̊C in NH3.
► ZnAl2O4:Mn2+ shows two green emission bands centered at 508 and 517 nm, respectively.
► A simple FED device was firstly prepared by using the synthesized ZnAl2O4:Mn2+.
► Under low-voltage excitation, it exhibits the bright green emission, high voltage brightness saturation, and high color purity.