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

Highlights: • Sr_1-xCa_xS:Mn²⁺ phosphors were synthesized by performing a solid-state reaction. • CL spectra were examined under electron excitation from 4 to 10 kV. • The ability to tune the color from greenish yellow to red was observed. • Sr_1-xCa_xS:Mn²⁺ phosphors revealed the promise for the use in CNT-FEDs. Sr_1-xCa_xS: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 Sr_1-xCa_xS:Mn²⁺ phosphors from greenish yellow to red confirms the promise of these phosphors for use in CNT-FEDs.