Mn-doped ZnS nanoparticles as efficient low-voltage cathodoluminescent phosphors

We have synthesized nanoparticles of ZnS doped with Mn for potential use as cathodoluminescent phosphors in field-emission displays (FEDs). We show th at the cathodoluminescent efficiency of particles less than or equal to 100 nm in diameter is within 40% of that of a commercial (micron-sized) phosph or when the electron-beam energy ranges between 500 and 3500 eV. The nanopa rticles exhibit less current saturation than larger-sized phosphors, an imp ortant feature for use in FEDs. Furthermore, the nanoparticles were anneale d at just 535 degrees C, hundreds of degrees below the processing temperatu res of standard phosphors. Finally, we discuss the effect of the particle s urface on low-voltage luminous efficiency. (C) 1999 American Institute of P hysics. [S0003-6951(99)02032-X].