UVC electroluminescence in Y2SiO5:Pr3+ powder and film phosphors

Abstract

The Pr3+-doped Y2SiO5 phosphor was used for UVC light. UVC light is used for sterilization, which is effective for almost all viruses and bacteria. The electroluminescent devices were fabricated based on Y2SiO5:Pr3+ phosphor. The electroluminescent devices were demonstrated in two types: powder EL and electrolyte EL. The Y2SiO5:Pr3+ phosphor powder was fabricated by a solid-state reaction method. The electroluminescent device of Y2SiO5:Pr3+ phosphor powder was fabricated through a screen-printing method. The emission showed two main peak in UVC spectra: wavelengths at 280 nm and 320 nm and also showed emissions in the visible region indicated by the green, yellow and red peaks. Its EL intensities versus voltages were exponentially increased, and its EL intensities versus frequency were linearly increased. The current density of the EL device for varying applied voltage was increased up to 1 mA/cm2 at 500 V. The Y2SiO5:Pr3+ phosphor film was fabricated by a spin coating method. The phosphor film was applied to the electrolyte EL device. The electrolyte EL device showed a 295 nm peak and 75 nm half-width. The electrolyte EL intensities versus voltages were linearly increased. However, electrolyte EL intensities versus frequency were increased up to 100 Hz and then decrease. The current density of electrolyte EL device at various applied voltage was linearly increased up to 5.8 mA/cm2 at 100 V and then saturated. The Y2SiO5:Pr3+ nano phosphor was prepared by a planetary milling. The electrolyte EL device of Y2SiO5:Pr3+ nano phosphor film was fabricated on Si wafer through an electrophoretic deposition. The electrolyte EL device showed a broad 295 nm UVC emission. The nano phosphor film’s electrolyte EL intensities versus voltages and frequency were linearly increased until 80 V and then decreased.