Effects of sintering temperature and phase transition on the photoluminescence and triboluminescence of manganese doped zinc sulfide

In this work, manganese doped zinc sulfide (ZnS: Mn2+) samples were synthesized by a solid-state method under various sintering temperature. With the increase of temperature, ZnS: Mn2+ was gradually evolved from zinc blende to wurtzite phase with particle size reduced. Further increasing the sintering temperature of wurtzite ZnS: Mn2+ could lead to a preferred orientation of crystal phase. The above physical structure evolutions aroused remarkably changes on the luminescent properties of ZnS: Mn2+, and the effects of sintering temperature and phase transition were investigated. The results suggested that ZnS: Mn2+ of wurtzite phase was more efficient for both photoluminescence and triboluminescence. This should be attributed to not only the enhanced excitation efficiency and piezoelectricity, but also the increased carrier density in traps and the beneficial kinetic order of ZnS: Mn2+ in wurtzite phase. The photoluminescence and triboluminescence of ZnS: Mn2+ showed different spectral shift behaviors along with the crystal phase variation, suggesting that they possessed different energy transfer pathways and thus the distinct dependence on crystal field and band gap. The presented research on the luminescent behaviors of ZnS: Mn2+ with varied crystal phase, especially for the content regarding to triboluminescence, should be useful to further guide the design and optimization of ZnS-based luminescent materials as well as the full reveal of its luminescent mechanisms.