Narrow-band green-emitting Cs3ZnCl5: Mn2+ phosphors with abnormal thermal quenching

Compounds with Cs3CoCl5 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 Cs3CoCl5 structure have great luminescence characteristics, thus it is more worthwhile to research Cl-based materials with higher electronegativity. Here, an Mn2+ activated Cs3ZnCl5 narrow band green emitting phosphor was developed and investigated in detail. Ternary alkaline chloride Cs3ZnCl5 was successfully prepared by a coprecipitation method. XRD refinement, SEM and XPS have proved the successful preparation of Cs3ZnCl5: 6%Mn2+ with a single phase. The electronic structure investigation clearly states that Cs3ZnCl5 has a large band gap with Eg∼4.467 eV. The Cs3ZnCl5: 6%Mn2+ 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 Cs3ZnCl5: 6%Mn2+ at room temperature, were studied. Over the temperature range of 30–120 °C, the thermal quenching performance of Cs3ZnCl5: 6%Mn2+ was investigated, and the related mechanism was discussed through thermoluminescence analysis. Electron traps transmit energy to the Mn2+ 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 Cs3ZnCl5: 6%Mn2+ could be served as a potential green-emitting phosphor for white light-emitting diodes.