Narrow-band green-emitting Cs 3 ZnCl 5 : Mn 2+ phosphors with abnormal thermal quenching

Compounds with Cs 3 CoCl 5 structure usually exhibit a large Debay temperature with a large band gap, which has been considered as new host materials for WLED application. Oxide materials of the Cs 3 CoCl 5 structure have great luminescence characteristics, thus it is more worthwhile to research Cl-based materials with higher electronegativity. Here, an Mn 2+ activated Cs 3 ZnCl 5 narrow band green emitting phosphor was developed and investigated in detail. Ternary alkaline chloride Cs 3 ZnCl 5 was successfully prepared by a coprecipitation method. XRD refinement, SEM and XPS have proved the successful preparation of Cs 3 ZnCl 5 : 6%Mn 2+ with a single phase. The electronic structure investigation clearly states that Cs 3 ZnCl 5 has a large band gap with Eg∼4.467 eV. The Cs 3 ZnCl 5 : 6%Mn 2+ phosphor can also generate green light with a peak wavelength of 525 nm and a fullwidth at half-maximum (FWHM) of 47 nm when excited by blue light at 451 nm. The luminescent property, as well as the concentration-dependent emission decay behavior of Cs 3 ZnCl 5 : 6%Mn 2+ at room temperature, were studied. Over the temperature range of 30–120 °C, the thermal quenching performance of Cs 3 ZnCl 5 : 6%Mn 2+ was investigated, and the related mechanism was discussed through thermoluminescence analysis. Electron traps transmit energy to the Mn 2+ luminescence center after 120 °C, which will increase the emission intensity. Finally, a blue light-pumped white LED was constructed using this phosphor in combination with commercially available red phosphors. The findings above suggested that Cs 3 ZnCl 5 : 6%Mn 2+ could be served as a potential green-emitting phosphor for white light-emitting diodes.