Fine tuning of the color of light emitted from Sr1-xCaxS:Mn2+ phosphors for CNT-FEDs

Sr1-xCaxS:Mn2+ phosphors with calcium ion mole fraction (x) values of 0, 0.2, 0.4, 0.6, 0.8, and 1 were synthesized from CaS, SrS, and MnS by carrying out solid-state reactions. Cathodoluminescence (CL) spectra of these phosphors were acquired using moderate voltages in the range 4-10 kV in order to assess their applicability to carbon nanotube field emission displays (CNT-FEDs). The wavelength at the maximum intensity of the CL spectra of the phosphors increases gradually from 549 to 602 nm, and then slightly decreases to 599 nm, as x is increased. This increase can be interpreted in terms of the crystal structures of the phosphors. The ability to tune the color of light emitted from the Sr1-xCaxS:Mn2+ phosphors from greenish yellow to red confirms the promise of these phosphors for use in CNT-FEDs.