A Dual-Emission Phosphor LiCaBO[sub 3]:Ce[sup 3+],Mn[sup 2+] with Energy Transfer for Near-UV LEDs

Abstract
A series of Ce3+Ce3+ and Mn2+Mn2+ co-doped LiCaBO3LiCaBO3 single composition phosphors were synthesized by a solid-state reaction method, and their luminescent properties had also been investigated. Ce3+Ce3+ and Mn2+Mn2+ co-doped LiCaBO3LiCaBO3 phosphors showed a blue and orange dual emission under the near-UV light excitation within the wavelength range of 325–375nm325–375nm , resulting from the 5d-4f5d-4f transitions of Ce3+Ce3+ and the d-dd-d forbidden transition of Mn2+Mn2+ , respectively. The energy transfer from Ce3+Ce3+ to Mn2+Mn2+ was investigated and demonstrated to be a resonance-type via a dipole-dipole mechanism with the critical distance of about 4.1Å4.1Å . The photoluminescence intensity ratio of blue and orange emission could be tuned by adjusting the concentration of Ce3+Ce3+ and Mn2+Mn2+ . The potential applications of these dual-emitting phosphors are the alternative blue and orange-emitting light emitting diode (LED) conversion phosphors due to their strong excitation bands in the wavelength range of 325–375nm325–375nm .