Orange electroluminescence from chemically synthesized zinc sulfide nanocrystals doped with manganese

Abstract The electroluminescence (EL) properties of chemically synthesized ZnS:Mn nanocrystals (NCs) with a crystallite size of approximately 4 nm were investigated utilizing EL devices with a structure of glass substrate/indium-tin oxide (ITO)/Si 3 N 4 /ZnS:Mn NC emission layer/Al. The emission layer was prepared by a screen-printing method. Orange EL emission, which is ascribed to the 4 T 1 – 6 A 1 transition of Mn 2+ ions, was observed at high electric fields of >3 MV/cm applying to the emission layer. Moreover, the Si 3 N 4 insulating layer was effective in improving the operation stability, resulting in the improvement of the maximum luminance. Consequently, the maximum luminance has been achieved to 1.7 cd/m 2 at 212 V 0-p with 1 kHz sinusoidal wave drive. The excitation mechanism of Mn 2+ ions is discussed using time-resolved EL spectra in comparison with time-resolved PL spectra.