Thin-film electroluminescent (EL) devices having a conductor-semiconductor-resistor-metal (CSRM) structure (In
2O
3-ZnS: Mn-ZnSe-Al), that are capable of dc excitation, have been prepared. The brightness is 50 fL and the external quantum efficiency is 5 × 10
-5. To clarify the effect of the ZnSe layer,

and

characteristics for dc excitation were studied at room temperature. The experimental results show that the ZnSe layer acts as a distributed resistive layer that protects the ZnS:Mn emitting layer against breakdown due to avalanche current.