Alkali borosilicate glasses doped with transition metals were studied to test their suitability as phosphor materials. The doped glasses would act as direct coatings on long wavelength ultraviolet and blue GaN and InGaN LEDs. The blue or ultraviolet LED emission would act as the excitation source, so that the combination of emission colours yields white light via additive mixing. The LED materials must be processed at moderate temperatures so a thermally suitable glass host is of importance. The transition metal ions that were studied are Cr3+ and Mn2+, as well as a reduced niobium containing glass that contains a mix of niobium oxidation states, primarily Nb4+ and Nb5+. The green coloured Cr3+ -containing glass was found to emit a weak red/near infrared light upon excitation with 450nm light.
