Thin-film electroluminescence device utilizing ZnS:Mn nanocrystals as emission layer

Abstract Luminescence properties of impurity-doped ZnS nanocrystals have been investigated for their application to a thin-film electroluminescence (TFEL) device as an emission layer. Two impurity-doped series with different emission mechanisms have been examined, i.e., Mn-doped ZnS nanocrystals for orange emission due to Mn 2+ 4 T 1 ( 4 G )– 6 A 1 ( 6 S ) transitions and Ag and Al co-doped ZnS nanocrystals for blue emission due to Al Zn + donor – Ag Zn − acceptor pair recombinations. Regarding photoluminescence (PL), with a reduction of the crystal size, PL efficiencies of the orange and blue bands increase. On the other hand, EL is observed only from ac-driven TFEL devices with ZnS:Mn nanocrystals.