White light emission from blue and near ultraviolet light-emitting diodes precoated with a Sr_3SiO_5:Ce^3+,Li^+ phosphor

White-light-emitting diodes (WLEDs) were fabricated by combining a yellow ${\mathrm{Sr}}_3{\mathrm{SiO}}_5:{\mathrm{Ce}}^{3+},{\mathrm{Li}}^{+}$ phosphor with a blue light-emitting diode (LED) ($460\mathrm{nm}$ chip) or a near ultraviolet (n-UV) LED ($405\mathrm{nm}$ chip), respectively. Color temperature $\left(T_c\right)$ of ${\mathrm{Sr}}_3{\mathrm{SiO}}_5:{\mathrm{Ce}}^{3+},{\mathrm{Li}}^{+}$-based WLEDs could be tuned from 6500 to $\mathrm{100,000}\mathrm{K}$ (blue LED pumping) and from 4900 to $\mathrm{50,000}\mathrm{K}$ (n-UV LED pumping) without mixing with other phosphors. The blue LED-pumped WLED showed excellent white light (luminous efficiency=$31.7\mathrm{lm}∕\mathrm{W}$, $T_c=6857\mathrm{K}$) at $20\mathrm{mA}$. This WLED showed a stable color coordinates property against an increase of the forward current. An n-UV LED-pumped WLED also showed bright white light ($25.0\mathrm{lm}∕\mathrm{W}$, $5784\mathrm{K}$) at $20\mathrm{mA}$.