Temperature behaviour of the orange and blue emissions in ZnS:Mn nanoparticles

Abstract

The temperature dependences of the orange and blue emissions in 10, 4.5, and 3nm ZnS:Mn nanoparticles were investigated. The orange emission is from the4T1–6A1 transition of Mn2+ ions and the blue emission is related to thedonor–acceptor recombination in the ZnS host. With increasing temperature, theblue emission has a red-shift. On the other hand, the peak energy of the orangeemission is only weakly dependent on temperature. The luminescence intensity ofthe orange emission decreases rapidly from 110 to 300 K for the 10 nm sample butincreases obviously for the 3 nm sample, whereas the emission intensity is nearlyindependent of temperature for the 4.5 nm sample. A thermally activatedcarrier-transfer model has been proposed to explain the observed abnormaltemperature behaviour of the orange emission in ZnS:Mn nanoparticles.