Cavity Effect in Nanocrystalline Porous Silicon Ballistic Lighting Device.

A planar light-emitting device was developed using a nanocrystalline porous Si layer as an energetic hot electron generator and a ZnS:Mn film as a luminescent film. Uniform orange light emission was observed at relatively low bias voltages. Furthermore, a cavity built using two Ag mirrors on both sides of the ZnS:Mn film operated well and effectively narrowed both the photoluminescence and electroluminescence (EL) spectra. The emission characteristics under the device operation in a three-electrode configuration clarified the EL mechanism based on the ballistic electron generation in the nanocrystalline Si layer followed by the direct excitation of the fluorescent film. The device, which provides a ballistic lighting concept for inorganic EL with a low driving voltage, is a very attractive all-thin-film surface-emitting light source for various applications. [ABSTRACT FROM AUTHOR]